DID is the OEM supplier of many Japanese and European brands. The main road racing and off-road sports teams are based on the technology of DID. DID 428VX: The development of 428VX is based on DID's vast experience in MotoGP and met through the use of the patented X-rings, even the most demanding requests. In comparison to the V-series equipped O-ring which has higher strength and 428VX higher wear resistance. - Long life and low friction from patented X-Ring gold colored outer plates, black inner plates (G & amp B gold and black).