Specially selected replacement springs to greatly improve functioning AND reduce trigger pull form the basis of a top-quality 1911 tuning job. 5 Wolff coil springs plus a factory-style, 3-leaf sear spring. Includes: Variable Power Recoil Spring which functions with a wider range of ammo than single power springs; Hammer Spring which lightens trigger pull; Extra Power Firing Pin Spring; New Magazine Catch; Series 80 Firing Pin Safety Block Spring; Plunger Tube Springs, plus the Sear Spring. Three kits - each with a different strength recoil spring. GM-452 - 16½ lb. Recoil Spring for standard factory ammo.