RK's O.E.M. Replacement Kits are designed for high-mileage performance and feature a 20,000 mile warranty on all components. Includes a premium Driven C45 steel alloy black case-hardened rear sprocket paired with Driven C45 steel case-hardened and quenched front sprocket. Kits feature RK's premium, lightweight RX- or XW-ring sealed racing chain in natural finish. Kits will contain O.E. gearing. Chain & Sprocket O.E. Kit