XXR 501 - The XXR 501 is technologically designed with a retro flavor to fit new wave tuner and old schools cars. The XXR is available in a wide range of finishes including: Hyper Silver, Black, Gun Metal, and Red and comes in 15 inch and 16 inch sizes. For quality assurance, all of XXR wheels are certified by the international standard on accreditation of ISO 9002 and QS 9000. The factory also obtained the qualification of Japanese VIA Standard on quality testing which guarantees that every wheel meets their vigorous testing standards. When you purchase XXR 501 wheels, rest assured that you will be getting one of the best on the market.