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 ZVM-X: As the successor to the proven high - performance chain ZVM2, ZVM-X is particularly suited to the various loads encountered in everyday life. In this case, the tensile strength only indicates the fracture load of a chain statically determined in the laboratory, but not the resistance to the forces occurring in practice. For this reason the ZVM-X focused primarily on strength in use. an increased tensile strength and -lower weight compared to ZVM2 - very high wear resistance and - up to 50% reduced friction losses due to patented X-ring technology Silver outer pockets, Silver inner pockets (S & S = Silver and Silver)