RK 520ZXW XW-Ring Chain Hypersports - GoldRK's ZXW series is ideal for both racing and general use. ZXW features technology derived from the MotoGP and FIM Suzuka 8 hour Endurance and has proven superiority with its 35 first place finishes out of 39 races at the FIM Suzuki 8 Hour Endurance Race. RK's XW Ring seals provide three contact lips and two lubrication pools to protect against dirt and debris, high speed abrasion, heat build up and the loss of lubricant under extreme conditions.