RK 520MXZ5 Chain - GoldThe RK 520MXZ5 features pins equipped with HCR Treatment (High Tech Chromium Carbide Layered), resulting in a tensile strength as high as 6800 Nm at a weight as light as 1. 43kg. Chromoly steel construction with seamless rollers and bushings combine to drastically improve wear resistance to more than twice that of normal non sealed chains. The 520MXZ5 arrives impregnated with a new, less tacky grease, which is less likely to attract dirt and debris.