The specific Collider2D attached to this Rigidbody2D to be used to detect contacts.
Can be used to select a specific Collider2D attached to this Rigidbody2D to be used to detect contacts. If this is selected then Rigidbody2D.SlideMovement.useAttachedTriggers is ignored.
See Also: Rigidbody2D.Slide and SlideResults.