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 designed with the requirements of the SX and MX racing in mind, and is therefore specially reinforced. The 428NZ rollers are made of round material and therefore have no seam. Weak points, as in rolls produced from wound sheet metal strips, are thus avoided. In addition, the rivets produced by the special process (SDH), which have a high surface hardness, speak for the 428NZ. - solid rolls of round material - specially hardened rivets (SDH technology)