Complete trigger system installs in five minutes without fitting or modification of parts on the trigger or your receiver. All adjustments are made with setscrews, eliminating the risk of ruining the trigger due to errors in fitting. Includes the JP Speed Hammer for fast lock time, plus "anti-walk" pins with button head cap screws for easy removal and reinstallation of the trigger system. Overtravel adjustment screw lets you set your trigger for a clean, crisp, single-stage release. Comes with two hammer springs: install the yellow spring to get a 3 to 3A 1/2 pull for competition or recreational shooting with non-military ammunition. The red spring gives a 3A 1/2 to 4 lb Mfg: J P Enterprises SPECS: Steel, black oxide finish. Models available for rifles with .154" dia. (military and current commercial rifles) or .169" diameter (Colt rifles) hammer and trigger pin holes. Measure your pins and select the correct kit. NOTE: Will not fit Colt rifles with pinned-in full-auto sear