Wilson Combat's Custom-Tune Spring Kits are designed to easily and inexpensively improve the action and functionality of your handgun. 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. Kit Includes:9 lb reduced power mainspring10 lb reduced power mainspring12 lb reduced power mainspring8 lb reduced power trigger rebound spring10 lb reduced power trigger rebound spring