This one piece duplicate of the factory RS bumper is designed to be used with 9" rear quarter panels (SC, ST, Carrera). It is designed with shorter bumperettes and dual exhaust cut outs. It can also be used on "69-"73 stock body cars by pushing the ends of the bumper in slightly. Average Weight is 8 LBS. Fits GT Racing rear fenders and flares (part #35-9, #36).