This kit replaces the hammer spring retainer, as well as the hammer spring, the poppet, and the trigger spring. The kit will fit any caliber of the Umarex Gauntlet. This kit gives you the ability to adjust the hammer spring tension; we also replace the hammer spring with a lower tension version, making the gun easier to cock, while not compromising performance. The replacement poppet has improved geometry to give better flow and higher potential power. The replacement trigger spring gives the gun a better trigger feel, and decreases the tension on the seer, making the gun more consistent to cock. When we installed this kit, we noted considerably easier cocking action, as well as a sizeable increase in the number of shots we got per charge.