DID is an OEM of many Japanese and European brands. Leading racing teams in the Road and off-road sports rely on the technology of DID. DID 428NZ: The 428NZ has been developed with regard to the requirements of the SX and MX racing sport and is therefore specially reinforced. The rollers of the 428NZ are made of round material and therefore do not have a seam. Weak points, such as rolls made from sheet metal strips, are thus avoided. In addition, rivets produced by a special process (SDH), which have a high surface hardness, speak for the 428NZ. - solid castors made of round material - specially hardened rivets (SDH technology)