Custom-Tune Spring, Kit, S&W, J 8# Reduced Power Hammer Spring and 13#, 14#, 15# Reduced Power Rebound Trigger Spring "CUSTOM-TUNE" Spring Kits are designed to easily and inexpensively improve your revolvers' action and functionality. These quality spring kits feature the finest gun springs available, made from high-tensile spring wire, for the finest possible action tuning jobs. Kits include the various springs necessary to assure reliable function, smooth operation, consistency, and long life. when only the best will do, WILSON COMBATA "CUSTOM-TUNE" Spring Kits are the only choice. "CUSTOM-TUNE" are available for most popular Revolvers. Revolver "Custom-Tune" Spring Kits lighten the trigger pull on single action revolvers and improve the single and double action trigger pull on double action revolvers. Double action kits contain assorted trigger rebound springs, allowing the selection of the lightest spring that will provide proper trigger return with your particular pistol. If you've never tried one of these kits, you won't believe the difference. Features: Fits S&W J Frame Centerfire Revolvers (not for rimfire) High tensile wire resists taking a set Reduced power spring assortment ensures lighter trigger pulls and reliable function Drop-in fit