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. 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. M-456 for the Colt Mustang .380 - Includes a 12 lb., extra ­power recoil spring with an extra power firing pin spring to ­improve functioning plus a reduced power, 20 lb. main spring (hammer spring) to lighten trigger pull, and a factory standard 23 lb. hammer spring.