Progressive 412 Shocks For Triumph Bonneville Speed Twin / Thruxton 1200 The 412 Series shocks are simply the best value shock on the market today with their simple, durable design. They will be an improvement to your motorcycle's suspension performance over the stock units. The doublewall steel body construction with nitrogen charged, multi-staged velocity sensitive valving gives you smooth, consistent damping. A five-position cam style preload adjuster lets you dial in your ride. Available in full show chrome or black with progressive rate springs in Standard or Heavy-Duty. Features: All Steel double wall damper with multistage velocity sensitive damping 5-position cam style preload adjuster High Pressure Gas Charged for consistent damping performance 1 Year Warranty