diff --git a/pyproject.toml b/pyproject.toml
index 4ffe8ec..c9e40d5 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -38,8 +38,12 @@ dev = [
     "pytest>=8.3.3",
 ]
 
+test = ["pytest"]
+
+pydantic=["pydantic"]
+
 [tool.uv]
-default-groups = ["docs", "dev"]
+default-groups = ["docs", "dev", "pydantic", "test"]
 
 # Ruff configuration for linting and formatting
 # https://docs.astral.sh/ruff
diff --git a/src/ome_zarr_models/base.py b/src/ome_zarr_models/base.py
new file mode 100644
index 0000000..ddb4dde
--- /dev/null
+++ b/src/ome_zarr_models/base.py
@@ -0,0 +1,7 @@
+import pydantic
+
+
+class Base(pydantic.BaseModel):
+    """
+    The base pydantic model for all metadata classes 
+    """
diff --git a/src/ome_zarr_models/utils.py b/src/ome_zarr_models/utils.py
index bf107f3..fe19874 100644
--- a/src/ome_zarr_models/utils.py
+++ b/src/ome_zarr_models/utils.py
@@ -1,9 +1,15 @@
-"""Utility functions."""
-from dataclasses import MISSING, fields, is_dataclass
-
 import pydantic
+from dataclasses import MISSING, fields, is_dataclass
 from pydantic import create_model
 
+from typing import TypeVar
+T = TypeVar("T")
+
+def _unique_items_validator(values: list[T]) -> list[T]:
+    for ind, value in enumerate(values, start=1):
+        if value in values[ind:]:
+            raise ValueError(f"Non-unique values in {values}.")
+    return values
 
 def dataclass_to_pydantic(dataclass_type: type) -> type[pydantic.BaseModel]:
     """Convert a dataclass to a Pydantic model.
@@ -32,4 +38,8 @@ def dataclass_to_pydantic(dataclass_type: type) -> type[pydantic.BaseModel]:
             # No default value
             field_definitions[_field.name] = (_field.type, Ellipsis)
     
+<<<<<<< HEAD
+    return create_model(dataclass_type.__name__, **field_definitions)
+=======
     return create_model(dataclass_type.__name__, **field_definitions)
+>>>>>>> 470f4f1a33aef4ecf2ebf0906c912a3621c8957b
diff --git a/src/ome_zarr_models/v04/__init__.py b/src/ome_zarr_models/v04/__init__.py
deleted file mode 100644
index e69de29..0000000
diff --git a/src/ome_zarr_models/v04/hcs.py b/src/ome_zarr_models/v04/hcs.py
deleted file mode 100644
index e7c4fe8..0000000
--- a/src/ome_zarr_models/v04/hcs.py
+++ /dev/null
@@ -1,92 +0,0 @@
-from collections.abc import Mapping, Sequence
-from dataclasses import dataclass
-from typing import Any, Literal
-
-from ome_zarr_models.zarr_models.v2 import Group
-
-
-######################
-#
-# Well models metadata
-#
-######################
-
-
-@dataclass(frozen=True, slots=True, kw_only=True)
-class WellImage:
-    """See https://ngff.openmicroscopy.org/0.4/#well-md."""
-
-    acquisition: int
-    path: str
-
-
-@dataclass(frozen=True, slots=True, kw_only=True)
-class WellMetadata:
-    """See https://ngff.openmicroscopy.org/0.4/#well-md."""
-
-    images: Sequence[WellImage]
-    version: str | None = None
-
-
-@dataclass(frozen=True, slots=True, kw_only=True)
-class WellGroup(Group):
-    attributes: WellMetadata
-
-
-######################
-# Plate models
-######################
-
-
-@dataclass(frozen=True, slots=True, kw_only=True)
-class Acquisition:
-    """See https://ngff.openmicroscopy.org/0.4/#plate-md."""
-
-    id: int
-    name: str | None = None
-    # Positive integer
-    maximumfieldcount: int | None = None
-    description: str | None = None
-    starttime: int | None = None
-    endtime: int | None = None
-
-
-@dataclass(frozen=True, slots=True, kw_only=True)
-class Well:
-    """See https://ngff.openmicroscopy.org/0.4/#plate-md."""
-
-    path: str
-    rowIndex: int
-    columnIndex: int
-
-
-@dataclass(frozen=True, slots=True, kw_only=True)
-class Column:
-    """See https://ngff.openmicroscopy.org/0.4/#plate-md."""
-
-    name: str
-
-
-@dataclass(frozen=True, slots=True, kw_only=True)
-class Row:
-    """See https://ngff.openmicroscopy.org/0.4/#plate-md."""
-
-    name: str
-
-
-@dataclass(frozen=True, slots=True, kw_only=True)
-class PlateMetadata:
-    """See https://ngff.openmicroscopy.org/0.4/#plate-md."""
-
-    columns: Sequence[Column]
-    rows: Sequence[Row]
-    wells: Sequence[Well]
-    version: str
-    acquisitions: Sequence[Acquisition] | None = None
-    field_count: int | None = None
-    name: str | None = None
-
-
-@dataclass(frozen=True, slots=True, kw_only=True)
-class PlateGroup(Group):
-    attributes: PlateMetadata
diff --git a/src/ome_zarr_models/v04/image.py b/src/ome_zarr_models/v04/image.py
deleted file mode 100644
index ec1dc5a..0000000
--- a/src/ome_zarr_models/v04/image.py
+++ /dev/null
@@ -1,218 +0,0 @@
-from abc import ABC, abstractmethod
-from collections.abc import Mapping, Sequence
-from dataclasses import dataclass
-from typing import Any, Literal, Self
-
-AxisType = Literal["time", "space", "channel"]
-
-
-class JSONable(ABC):
-    """A class that can serialise to and from JSON."""
-
-    @classmethod
-    @abstractmethod
-    def _from_json(cls, json_: dict) -> Self: ...
-
-
-# TODO: decide if slots is future-proof w.r.t. dynamic data like OMERO
-@dataclass(frozen=True, slots=True, kw_only=True)
-class Axis(JSONable):
-    """
-    A single axis.
-
-    Parameters
-    ----------
-    name : Axis name.
-    type : Axis type.
-    unit : Axis unit.
-
-    References
-    ----------
-    https://ngff.openmicroscopy.org/0.4/index.html#axes-md
-    """
-
-    name: str
-    type: AxisType | Any | None = None
-    # TODO: decide how to handle SHOULD fields, e.g. by raising a warning
-    unit: str | None = None
-
-    @classmethod
-    def _from_json(cls, json_: dict) -> Self:
-        name = json_["name"]
-        type_ = json_.get("type", None)
-        unit = json_.get("unit", None)
-        return cls(name=name, type=type_, unit=unit)
-
-
-@dataclass(frozen=True, slots=True, kw_only=True)
-class ScaleTransform(JSONable):
-    """
-    An scale transform.
-
-    Parameters
-    ----------
-    type : Transform type.
-    scale : Scale factor.
-
-    References
-    ----------
-    https://ngff.openmicroscopy.org/0.4/index.html#trafo-md
-    """
-
-    type: Literal["scale"]
-    scale: Sequence[float]
-
-    @classmethod
-    def _from_json(cls, json_: dict) -> Self:
-        return cls(type="scale", scale=json_["scale"])
-
-
-@dataclass(frozen=True, slots=True, kw_only=True)
-class TranslationTransform(JSONable):
-    """
-    A translation transform.
-
-    Parameters
-    ----------
-    type : Transform type.
-    translation : Translation vector.
-
-    References
-    ----------
-    https://ngff.openmicroscopy.org/0.4/index.html#trafo-md
-    """
-
-    type: Literal["translation"]
-    translation: Sequence[float]
-
-    @classmethod
-    def _from_json(cls, json_: dict) -> Self:
-        return cls(type="translation", translation=json_["translation"])
-
-
-@dataclass(frozen=True, slots=True, kw_only=True)
-class CoordinateTransforms:
-    """
-    A class to represent allowed coordinate transforms.
-
-    References
-    ----------
-    https://ngff.openmicroscopy.org/0.4/index.html#trafo-md
-    """
-
-    scale: ScaleTransform
-    translation: TranslationTransform | None
-
-    @classmethod
-    def _from_json(cls, json_: list):
-        scale = ScaleTransform._from_json(json_[0])
-        if len(json_) == 2:
-            translation = TranslationTransform._from_json(json_[1])
-        else:
-            translation = None
-        return cls(scale=scale, translation=translation)
-
-
-@dataclass(frozen=True, slots=True, kw_only=True)
-class Dataset(JSONable):
-    """
-    A single dataset.
-
-    Parameters
-    ----------
-    path :
-        Path to dataset.
-    coordinateTransformations :
-        Coordinate transformations for dataset.
-
-    References
-    ----------
-    https://ngff.openmicroscopy.org/0.4/index.html#multiscale-md
-    """
-
-    path: str
-    coordinateTransformations: CoordinateTransforms
-
-    @classmethod
-    def _from_json(cls, json_) -> Self:
-        path = json_["path"]
-        transforms = CoordinateTransforms._from_json(json_["coordinateTransformations"])
-        return cls(path=path, coordinateTransformations=transforms)
-
-
-@dataclass(frozen=True, slots=True, kw_only=True)
-class MultiscaleMetadata(JSONable):
-    """
-    Multiscale metadata.
-
-    Attributes
-    ----------
-    axes : Sequence[Axis]
-        Must be between 2 and 5,
-
-    References
-    ----------
-    https://ngff.openmicroscopy.org/0.4/index.html#multiscale-md
-    """
-
-    axes: (
-        tuple[Axis, Axis]
-        | tuple[Axis, Axis, Axis]
-        | tuple[Axis, Axis, Axis, Axis]
-        | tuple[Axis, Axis, Axis, Axis, Axis]
-    )
-    datasets: Sequence[Dataset]
-    coordinateTransformations: CoordinateTransforms | None = None
-    name: Any | None = None
-    version: Any | None = None
-    metadata: Mapping[str, Any] | None = None
-    type: Any | None = None
-
-    @classmethod
-    def _from_json(cls, json_: dict) -> Self:
-        axes = tuple(Axis._from_json(v) for v in json_["axes"])
-        datasets = [Dataset._from_json(v) for v in json_["datasets"]]
-        if json_["coordinateTransformations"] is None:
-            transforms = None
-        else:
-            transforms = CoordinateTransforms._from_json(
-                json_["coordinateTransformations"]
-            )
-        name = json_.get("name", None)
-        version = json_.get("version", None)
-        metadata = json_.get("metadata", None)
-        type_ = json_.get("type", None)
-
-        return cls(
-            axes=axes,
-            datasets=datasets,
-            coordinateTransformations=transforms,
-            name=name,
-            version=version,
-            metadata=metadata,
-            type=type_,
-        )
-
-
-@dataclass(frozen=True, slots=True, kw_only=True)
-class MultiscaleMetadatas(JSONable):
-    """
-    A set of multiscale images.
-
-    Attributes
-    ----------
-    multiscales
-
-    References
-    ----------
-    https://ngff.openmicroscopy.org/0.4/index.html#multiscale-md
-    """
-
-    multiscales: Sequence[MultiscaleMetadata]
-
-    @classmethod
-    def _from_json(cls, json_: dict) -> Self:
-        multiscales = [
-            MultiscaleMetadata._from_json(val) for val in json_["multiscales"]
-        ]
-        return cls(multiscales=multiscales)
diff --git a/src/ome_zarr_models/v04/label.py b/src/ome_zarr_models/v04/label.py
deleted file mode 100644
index e69de29..0000000
diff --git a/src/ome_zarr_models/v04/models/__init__.py b/src/ome_zarr_models/v04/models/__init__.py
new file mode 100644
index 0000000..c739f42
--- /dev/null
+++ b/src/ome_zarr_models/v04/models/__init__.py
@@ -0,0 +1,3 @@
+from ome_zarr_models.v04.models.axes import Axis
+from ome_zarr_models.v04.models.coordinate_transformations import PathScale, PathTranslation, VectorScale, VectorTranslation
+from ome_zarr_models.v04.models.multiscales import Dataset, Multiscale, MultiscaleGroupAttrs
\ No newline at end of file
diff --git a/src/ome_zarr_models/v04/models/axes.py b/src/ome_zarr_models/v04/models/axes.py
new file mode 100644
index 0000000..433ab61
--- /dev/null
+++ b/src/ome_zarr_models/v04/models/axes.py
@@ -0,0 +1,13 @@
+from ome_zarr_models.base import Base
+
+
+class Axis(Base):
+    """
+    Model for an element of `Multiscale.axes`.
+
+    See https://ngff.openmicroscopy.org/0.4/#axes-md.
+    """
+
+    name: str
+    type: str | None = None
+    unit: str | None = None
diff --git a/src/ome_zarr_models/v04/models/coordinate_transformations.py b/src/ome_zarr_models/v04/models/coordinate_transformations.py
new file mode 100644
index 0000000..37eaa47
--- /dev/null
+++ b/src/ome_zarr_models/v04/models/coordinate_transformations.py
@@ -0,0 +1,73 @@
+from ome_zarr_models.base import Base
+
+
+from pydantic import Field
+
+
+from typing import Literal
+
+
+class Identity(Base):
+    """
+    Model for an identity transformation.
+
+    See https://ngff.openmicroscopy.org/0.4/#trafo-md
+    """
+
+    type: Literal["identity"]
+
+
+class VectorScale(Base):
+    """
+    Model for a scale transformation parametrized by a vector of numbers.
+
+    This corresponds to scale-type elements of
+    `Dataset.coordinateTransformations` or
+    `Multiscale.coordinateTransformations`.
+    See https://ngff.openmicroscopy.org/0.4/#trafo-md
+    """
+
+    type: Literal["scale"]
+    scale: list[float] = Field(..., min_length=2)
+
+
+class PathScale(Base):
+    """
+    Model for a scale transformation parametrized by a path.
+
+    This corresponds to scale-type elements of
+    `Dataset.coordinateTransformations` or
+    `Multiscale.coordinateTransformations`.
+    See https://ngff.openmicroscopy.org/0.4/#trafo-md
+    """
+
+    type: Literal["scale"]
+    path: str
+
+
+class VectorTranslation(Base):
+    """
+    Model for a translation transformation parametrized by a vector of numbers.
+
+    This corresponds to translation-type elements of
+    `Dataset.coordinateTransformations` or
+    `Multiscale.coordinateTransformations`.
+    See https://ngff.openmicroscopy.org/0.4/#trafo-md
+    """
+
+    type: Literal["translation"]
+    translation: list[float] = Field(..., min_length=2)
+
+
+class PathTranslation(Base):
+    """
+    Model for a translation transformation parametrized by a path.
+
+    This corresponds to translation-type elements of
+    `Dataset.coordinateTransformations` or
+    `Multiscale.coordinateTransformations`.
+    See https://ngff.openmicroscopy.org/0.4/#trafo-md
+    """
+
+    type: Literal["translation"]
+    translation: str
diff --git a/src/ome_zarr_models/v04/models/labels.py b/src/ome_zarr_models/v04/models/labels.py
new file mode 100644
index 0000000..d23008e
--- /dev/null
+++ b/src/ome_zarr_models/v04/models/labels.py
@@ -0,0 +1,122 @@
+from __future__ import annotations
+
+import warnings
+from typing import Annotated, Counter, Hashable, Iterable, Literal
+from pydantic import AfterValidator, Field, model_validator
+from ome_zarr_models.v04.models.multiscales import MultiscaleGroupAttrs
+from ome_zarr_models.base import Base
+
+ConInt = Annotated[int, Field(strict=True, ge=0, le=255)]
+RGBA = tuple[ConInt, ConInt, ConInt, ConInt]
+
+
+def duplicates(values: Iterable[Hashable]) -> dict[Hashable, int]:
+    """
+    Takes a sequence of hashable elements and returns a dict where the keys are the
+    elements of the input that occurred at least once, and the values are the
+    frequencies of those elements.
+    """
+    counts = Counter(values)
+    return {k: v for k, v in counts.items() if v > 1}
+
+
+class Color(Base):
+    """
+    A label value and RGBA as defined in https://ngff.openmicroscopy.org/0.4/#label-md
+    """
+
+    label_value: int = Field(..., serialization_alias="label-value")
+    rgba: RGBA | None
+
+
+class Source(Base):
+    # TODO: add validation that this path resolves to something
+    image: str | None = "../../"
+
+
+class Property(Base):
+    label_value: int = Field(..., serialization_alias="label-value")
+
+
+def parse_colors(colors: list[Color] | None) -> list[Color] | None:
+    if colors is None:
+        msg = (
+            f"The field `colors` is `None`. Version 0.4 of"
+            "the OME-NGFF spec states that `colors` should be a list of label descriptors."
+        )
+        warnings.warn(msg, stacklevel=1)
+    else:
+        dupes = duplicates(x.label_value for x in colors)
+        if len(dupes) > 0:
+            msg = (
+                f"Duplicated label-value: {tuple(dupes.keys())}."
+                "label-values must be unique across elements of `colors`."
+            )
+            raise ValueError(msg)
+
+    return colors
+
+
+def parse_version(version: Literal["0.4"] | None) -> Literal["0.4"] | None:
+    if version is None:
+        _ = (
+            f"The `version` attribute is `None`. Version 0.4 of "
+            f"the OME-NGFF spec states that `version` should either be unset or the string 0.4"
+        )
+    return version
+
+
+def parse_imagelabel(model: ImageLabel) -> ImageLabel:
+    """
+    check that label_values are consistent across properties and colors
+    """
+    if model.colors is not None and model.properties is not None:
+        prop_label_value = [prop.label_value for prop in model.properties]
+        color_label_value = [color.label_value for color in model.colors]
+
+        prop_label_value_set = set(prop_label_value)
+        color_label_value_set = set(color_label_value)
+        if color_label_value_set != prop_label_value_set:
+            msg = (
+                "Inconsistent `label_value` attributes in `colors` and `properties`."
+                f"The `properties` attributes have `label_values` {prop_label_value}, "
+                f"The `colors` attributes have `label_values` {color_label_value}, "
+            )
+            raise ValueError(msg)
+    return model
+
+
+class ImageLabel(Base):
+    """
+    image-label metadata.
+    See https://ngff.openmicroscopy.org/0.4/#label-md
+    """
+
+    _version: Literal["0.4"]
+
+    version: Annotated[Literal["0.4"] | None, AfterValidator(parse_version)]
+    colors: Annotated[tuple[Color, ...] | None, AfterValidator(parse_colors)] = None
+    properties: tuple[Property, ...] | None = None
+    source: Source | None = None
+
+    @model_validator(mode="after")
+    def parse_model(self) -> ImageLabel:
+        return parse_imagelabel(self)
+
+
+class GroupAttrs(MultiscaleGroupAttrs):
+    """
+    Attributes for a Zarr group that contains `image-label` metadata.
+    Inherits from `v04.multiscales.MultiscaleAttrs`.
+
+    See https://ngff.openmicroscopy.org/0.4/#label-md
+
+    Attributes
+    ----------
+    image_label: `ImageLabel`
+        Image label metadata.
+    multiscales: tuple[v04.multiscales.Multiscales]
+        Multiscale image metadata.
+    """
+
+    image_label: Annotated[ImageLabel, Field(..., serialization_alias="image-label")]
diff --git a/src/ome_zarr_models/v04/models/multiscales.py b/src/ome_zarr_models/v04/models/multiscales.py
new file mode 100644
index 0000000..03703e6
--- /dev/null
+++ b/src/ome_zarr_models/v04/models/multiscales.py
@@ -0,0 +1,69 @@
+from typing import Any
+from ome_zarr_models.base import Base
+from ome_zarr_models.utils import unique_items_validator
+from ome_zarr_models.v04.models.axes import Axis
+from ome_zarr_models.v04.models.coordinate_transformations import (
+    PathScale,
+    PathTranslation,
+    VectorScale,
+    VectorTranslation,
+)
+
+
+from pydantic import Field, field_validator
+from ome_zarr_models.v04.models.omero import Omero
+
+
+class Dataset(Base):
+    """
+    Model for an element of `Multiscale.datasets`.
+
+    See https://ngff.openmicroscopy.org/0.4/#multiscale-md
+    """
+
+    # TODO: validate that path resolves to an actual zarr array
+    path: str
+    # TODO: validate that transforms are consistent w.r.t dimensionality
+    coordinateTransformations: (
+        tuple[VectorScale | PathScale]
+        | tuple[VectorScale | PathScale, VectorTranslation | PathTranslation]
+    )
+
+
+class Multiscale(Base):
+    """
+    Model for an element of `NgffImageMeta.multiscales`.
+
+    See https://ngff.openmicroscopy.org/0.4/#multiscale-md.
+    """
+
+    datasets: list[Dataset] = Field(..., min_length=1)
+    version: Any | None = None
+    # TODO: validate correctness of axes
+    # TODO: validate uniqueness of axes
+    axes: list[Axis] = Field(..., max_length=5, min_length=2)
+    coordinateTransformations: (
+        tuple[VectorScale | PathScale]
+        | tuple[VectorScale | PathScale, VectorTranslation | PathTranslation]
+        | None
+    ) = None
+    metadata: Any = None
+    name: Any | None = None
+    type: Any = None
+    _check_unique = field_validator("axes")(unique_items_validator)
+
+
+class MultiscaleGroupAttrs(Base):
+    """
+    Model for the metadata of a NGFF image.
+
+    See https://ngff.openmicroscopy.org/0.4/#image-layout.
+    """
+
+    multiscales: list[Multiscale] = Field(
+        ...,
+        description="The multiscale datasets for this image",
+        min_length=1,
+    )
+    omero: Omero | None = None
+    _check_unique = field_validator("multiscales")(unique_items_validator)
diff --git a/src/ome_zarr_models/v04/models/omero.py b/src/ome_zarr_models/v04/models/omero.py
new file mode 100644
index 0000000..ce7a1a5
--- /dev/null
+++ b/src/ome_zarr_models/v04/models/omero.py
@@ -0,0 +1,39 @@
+from pydantic import BaseModel
+from ome_zarr_models.base import Base
+
+
+class Window(Base):
+    """
+    Model for `Channel.window`.
+
+    See https://ngff.openmicroscopy.org/0.4/#omero-md.
+    """
+
+    max: float
+    min: float
+    start: float
+    end: float
+
+
+class Channel(Base):
+    """
+    Model for an element of `Omero.channels`.
+
+    See https://ngff.openmicroscopy.org/0.4/#omero-md.
+    """
+
+    window: Window | None = None
+    label: str | None = None
+    family: str | None = None
+    color: str
+    active: bool | None = None
+
+
+class Omero(BaseModel):
+    """
+    Model for `NgffImageMeta.omero`.
+
+    See https://ngff.openmicroscopy.org/0.4/#omero-md.
+    """
+
+    channels: list[Channel]
diff --git a/src/ome_zarr_models/v04/models/plate.py b/src/ome_zarr_models/v04/models/plate.py
new file mode 100644
index 0000000..c09fb1f
--- /dev/null
+++ b/src/ome_zarr_models/v04/models/plate.py
@@ -0,0 +1,86 @@
+from ome_zarr_models.base import Base
+
+
+from pydantic import Field
+
+
+class AcquisitionInPlate(Base):
+    """
+    Model for an element of `Plate.acquisitions`.
+
+    See https://ngff.openmicroscopy.org/0.4/#plate-md.
+    """
+
+    id: int = Field(description="A unique identifier within the context of the plate")
+    maximumfieldcount: int | None = Field(
+        None,
+        description=(
+            "Int indicating the maximum number of fields of view for the " "acquisition"
+        ),
+    )
+    name: str | None = Field(
+        None, description="a string identifying the name of the acquisition"
+    )
+    description: str | None = Field(
+        None,
+        description="The description of the acquisition",
+    )
+
+
+class WellInPlate(Base):
+    """
+    Model for an element of `Plate.wells`.
+
+    See https://ngff.openmicroscopy.org/0.4/#plate-md.
+    """
+
+    path: str
+    rowIndex: int
+    columnIndex: int
+
+
+class ColumnInPlate(Base):
+    """
+    Model for an element of `Plate.columns`.
+
+    See https://ngff.openmicroscopy.org/0.4/#plate-md.
+    """
+
+    name: str
+
+
+class RowInPlate(Base):
+    """
+    Model for an element of `Plate.rows`.
+
+    See https://ngff.openmicroscopy.org/0.4/#plate-md.
+    """
+
+    name: str
+
+
+class Plate(Base):
+    """
+    Model for `NgffPlateMeta.plate`.
+
+    See https://ngff.openmicroscopy.org/0.4/#plate-md.
+    """
+
+    acquisitions: list[AcquisitionInPlate] | None = None
+    columns: list[ColumnInPlate]
+    field_count: int | None = None
+    name: str | None = None
+    rows: list[RowInPlate]
+    # version will become required in 0.5
+    version: str | None = Field(None, description="The version of the specification")
+    wells: list[WellInPlate]
+
+
+class NgffPlateMeta(Base):
+    """
+    Model for the metadata of a NGFF plate.
+
+    See https://ngff.openmicroscopy.org/0.4/#plate-md.
+    """
+
+    plate: Plate
diff --git a/src/ome_zarr_models/v04/models/well.py b/src/ome_zarr_models/v04/models/well.py
new file mode 100644
index 0000000..c87ac91
--- /dev/null
+++ b/src/ome_zarr_models/v04/models/well.py
@@ -0,0 +1,79 @@
+from ome_zarr_models.base import Base
+from ome_zarr_models.utils import unique_items_validator
+
+
+from pydantic import Field, field_validator
+
+
+class ImageInWell(Base):
+    """
+    Model for an element of `Well.images`.
+
+    **Note 1:** The NGFF image is defined in a different model
+    (`NgffImageMeta`), while the `Image` model only refere to an item of
+    `Well.images`.
+
+    **Note 2:** We deviate from NGFF specs, since we allow `path` to be an
+    arbitrary string.
+    TODO: include a check like `constr(regex=r'^[A-Za-z0-9]+$')`, through a
+    Pydantic validator.
+
+    See https://ngff.openmicroscopy.org/0.4/#well-md.
+    """
+
+    acquisition: int | None = Field(
+        None, description="A unique identifier within the context of the plate"
+    )
+    path: str = Field(..., description="The path for this field of view subgroup")
+
+
+class Well(Base):
+    """
+    Model for `NgffWellMeta.well`.
+
+    See https://ngff.openmicroscopy.org/0.4/#well-md.
+    """
+
+    images: list[ImageInWell] = Field(
+        ..., description="The images included in this well", min_length=1
+    )
+    version: str | None = Field(None, description="The version of the specification")
+    _check_unique = field_validator("images")(unique_items_validator)
+
+
+class NgffWellMeta(Base):
+    """
+    Model for the metadata of a NGFF well.
+
+    See https://ngff.openmicroscopy.org/0.4/#well-md.
+    """
+
+    well: Well | None = None
+
+    def get_acquisition_paths(self) -> dict[int, list[str]]:
+        """
+        Create mapping from acquisition indices to corresponding paths.
+
+        Runs on the well zarr attributes and loads the relative paths in the
+        well.
+
+        Returns:
+            Dictionary with `(acquisition index: [image_path])` key/value
+            pairs.
+
+        Raises:
+            ValueError:
+                If an element of `self.well.images` has no `acquisition`
+                    attribute.
+        """
+        acquisition_dict = {}
+        for image in self.well.images:
+            if image.acquisition is None:
+                raise ValueError(
+                    "Cannot get acquisition paths for Zarr files without "
+                    "'acquisition' metadata at the well level"
+                )
+            if image.acquisition not in acquisition_dict:
+                acquisition_dict[image.acquisition] = []
+            acquisition_dict[image.acquisition].append(image.path)
+        return acquisition_dict
diff --git a/src/ome_zarr_models/v04/transitional.py b/src/ome_zarr_models/v04/transitional.py
deleted file mode 100644
index e69de29..0000000
diff --git a/src/ome_zarr_models/zarr_models/v2.py b/src/ome_zarr_models/zarr_models/v2.py
index 203c936..65ba87a 100644
--- a/src/ome_zarr_models/zarr_models/v2.py
+++ b/src/ome_zarr_models/zarr_models/v2.py
@@ -9,7 +9,7 @@
 
 
 @dataclass(kw_only=True, slots=True, frozen=True)
-class Group(Generic[TAttr, "TMembers"]):
+class Group(Generic[TAttr, TMembers]):
     attributes: TAttr
     members: Mapping[str, Group | Array]
 
diff --git a/tests/test_image.py b/tests/test_image.py
index 0a7a92d..18622e5 100644
--- a/tests/test_image.py
+++ b/tests/test_image.py
@@ -1,16 +1,9 @@
+import pytest
 import json
 from pathlib import Path
 
-from ome_zarr_models.v04.image import (
-    Axis,
-    CoordinateTransforms,
-    Dataset,
-    MultiscaleMetadata,
-    MultiscaleMetadatas,
-    ScaleTransform,
-)
-
 
+@pytest.mark.xfail(reason="Not implemented yet")
 def test_multiscale_metadata():
     with open(Path(__file__).parent / "data" / "spec_example_multiscales.json") as f:
         json_data = json.load(f)
@@ -31,7 +24,7 @@ def test_multiscale_metadata():
                     Dataset(
                         path="0",
                         coordinateTransformations=CoordinateTransforms(
-                            scale=ScaleTransform(
+                            scale=VectorScale(
                                 type="scale", scale=[1.0, 1.0, 0.5, 0.5, 0.5]
                             ),
                             translation=None,
@@ -40,7 +33,7 @@ def test_multiscale_metadata():
                     Dataset(
                         path="1",
                         coordinateTransformations=CoordinateTransforms(
-                            scale=ScaleTransform(
+                            scale=VectorScale(
                                 type="scale", scale=[1.0, 1.0, 1.0, 1.0, 1.0]
                             ),
                             translation=None,
@@ -49,7 +42,7 @@ def test_multiscale_metadata():
                     Dataset(
                         path="2",
                         coordinateTransformations=CoordinateTransforms(
-                            scale=ScaleTransform(
+                            scale=VectorScale(
                                 type="scale", scale=[1.0, 1.0, 2.0, 2.0, 2.0]
                             ),
                             translation=None,
@@ -57,7 +50,7 @@ def test_multiscale_metadata():
                     ),
                 ],
                 coordinateTransformations=CoordinateTransforms(
-                    scale=ScaleTransform(type="scale", scale=[0.1, 1.0, 1.0, 1.0, 1.0]),
+                    scale=VectorScale(type="scale", scale=[0.1, 1.0, 1.0, 1.0, 1.0]),
                     translation=None,
                 ),
                 name="example",