Custom Tune Spring Kit, Glock 17/17L/20/20/22. 4# Reduced Power Hammer Spring, 15# Reduced Power Recoil Spring, 19# Extra Power Recoil Spring. Pkg. Includes: Reduced Power Hammer Spring, Reduced Power Recoil Spring, and Extra Power Recoil Spring. "CUSTOM-TUNE" Spring Kits are designed to easily and inexpensively improve your pistols' 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 COMBATГ�’вЂ�šÐ“‘вЂ�šÐ“�’ВІГ�’вЂ�™Ð“‘в„�žÐ“�’вЂ�šÐ“�žÐ²â€šÂ¬Ð•ÐŽÐ“�’’® "CUSTOM-TUNE" Spring Kits are the only choice. "CUSTOM-TUNE" Spring Kits are available for most popular center-fire Autos and Revolvers. Pistol "Custom-Tune" Spring Kits include the following springs to enhance the reliability, function, safety, and life of your center-fire pistol: Reduced Power Hammer Spring - Reduces hammer tension for reduced trigger pull of up to 25 percent. This provides ease of operation, and improves ejection thus increasing reliability. Extra Power Firing Pin Spring - Increases firing pin spring tension, providing added protection against accidental discharge if pistol is dropped. Reduced Power Recoil Spring - Provides reduced spring tension for reliable ejection of "reduced power" practice rounds. Extra Power Recoil Spring - Provides increased spring tension for "full house" factory loads. Also, improves feeding reliability and pistol life.