A closure plug for an access aperture for a towing hook on the bumper of a vehicle

A closure plug (4) for an access aperture for a towing hook on the bumper (2) of a vehicle which includes a coupling element (13) for coupling the plug (4) to the bumper (2) and a closure wall (5) for closing an aperture (3) in the bumper and including a weakened portion (9) which is resiliently deformable by the insertion of the towing hook through the closure wall (5).