S&S Cycle Secondary Cam Chain For Harley Twin Cam Engineered for high-output Twin Cam builds, this heavy-duty secondary cam chain is designed to provide the structural integrity required for managing increased horsepower. Each link is comprised of heat-treated components and features precision machining to minimize stretch, ensuring engine timing remains consistent under demanding conditions. This essential component is vital for riders aiming to enhance valvetrain durability while reducing maintenance intervals on their performance motorcycles. Features: Direct OEM Replacement Increased Chain Life 11 Stronger Replaces OEM 25683-06