# transformWriteCallbackTarget

> Get/Set the custom Object that implements the PhysicsCallbacks.ITransformWriteCallback to which PhysicsEvents.TransformWriteEvent and PhysicsEvents.TransformTweenWriteEvent will be sent. The callback will only occur if _transformWriteMode is set to PhysicsWorld.TransformWriteMode.Custom and there are _bodyUpdateEvents available. The object assigned here will be kept alive, not allowing the GC to dispose of it. To remove the object assigned here, set the callback target to NULL.

## Definition

* **Type:** Property
* **Namespace:** [Unity.U2D.Physics](/engine/6000.7/script-reference/unity/u2d/physics.md)
* **Assembly:** UnityEngine.PhysicsCore2DModule

```csharp
public object transformWriteCallbackTarget { get; set; }
```