Reduced Power Tune-Up Pak fits 10/22® in all calibers. Includes an extra power hammer spring, reduced power trigger spring, and reduced power sear spring to improve let-off and reduce trigger pull, perfect for competition. Tune-Up Pak fits all calibers of 10/22®. Includes an extra power hammer spring, extra power trigger spring, and reduced power sear spring for a clean, crisp trigger pull, perfect for hunting. For an even smoother, lighter-feeling trigger pull, install the reduced power (RP) trigger/sear spring. Tune-Up Paks do not include recoil springs.