diff --git a/raillabel/json_format/coordinate_system.py b/raillabel/json_format/coordinate_system.py
index d8815a0..7af85e1 100644
--- a/raillabel/json_format/coordinate_system.py
+++ b/raillabel/json_format/coordinate_system.py
@@ -6,7 +6,8 @@
 from typing import Literal
 
 from pydantic import BaseModel
-from transform_data import JSONTransformData
+
+from .transform_data import JSONTransformData
 
 
 class JSONCoordinateSystem(BaseModel):
diff --git a/raillabel/json_format/element_data_pointer.py b/raillabel/json_format/element_data_pointer.py
new file mode 100644
index 0000000..0ac6623
--- /dev/null
+++ b/raillabel/json_format/element_data_pointer.py
@@ -0,0 +1,24 @@
+# Copyright DB InfraGO AG and contributors
+# SPDX-License-Identifier: Apache-2.0
+
+from __future__ import annotations
+
+from typing import Literal
+
+from pydantic import BaseModel
+
+from .frame_interval import JSONFrameInterval
+
+
+class JSONElementDataPointer(BaseModel):
+    """A pointer to element data of elements.
+
+    It is indexed by 'name', and containing information about the element data type, for example,
+    bounding box, cuboid, and the frame intervals in which this element_data exists within an
+    element. That means, these pointers can be used to explore element data dynamic information
+    within the JSON content.
+    """
+
+    attribute_pointers: dict[str, Literal["num", "text", "boolean", "vec"]]
+    frame_intervals: list[JSONFrameInterval]
+    type: Literal["bbox", "num", "poly2d", "poly3d", "cuboid", "vec"]