Rear RC-40 twin box system to fit catalyst for cars built late 1991 on SPI(not early carb coopers). It has the hanger rods fited for mounting onto the rubber type straps. This makes it a twin box system with a little throatier pleasing note, but a much better flowing efficient system. Oval rear and round centre silencers. Theinstallation is done atyour own risk. According totraffic regulationsnot allowed.