The 412 Series shocks are simply the best value shock the Progressive offers. The 412's simple, durable design means they will be an improvement to your motorcycle's suspension performance for as long as you are riding it. The double-wall 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 whether you're a light rider or heavy hitter. Step into suspension that works for you.