RK is the leading manufacturer of motorbike drive chains in Japan. For more than 40 years, RK supplies all well-known Japanese motorcycle manufacturers as original equipment. Also in racing RK is the first choice of many teams in the MotoGP, in motocross or even at the Paris-Dakar Rally. RK MRU: The MRU chain has been developed for low-power motorcycles that are OEM equipped with a non-sealed standard chain. - U-ring chain - Loss of lubricant is avoided - Ultra thin sealing ring - Extremely narrow width - Up to 100% longer life compared to unsealed standard chains