The CMC 2-Stage trigger easily replaces your AR-15's gritty, heavy factory trigger and gives you a smooth, consistent, two-stage pull with a crisp, clean break, and a short reset. It's based on the drop-in trigger module originally designed by competition shooter Chip McCormick to provide all the advantages of a fine, match-grade trigger without the hand-fitting and trial-and-error. These two-stage CMC triggers come pre-set from the factory with a variety of first ("set") and second ("release") stage pull weights, so you can choose a combination that's best for your kind of shooting. And you can choose between a traditional Curved trigger shoe or Mfg: Cmc Triggers SPECS: Hammer/Trigger - Steel, blued finish. Housing - Steel, in-the-white. Fixed first/second stage pull weights are not user-adjustable. Includes two (2) Chicago-style center pins. Fits AR-15 with .154" diameter trigger and hammer pins. Also works with AR-308s that use AR-15 triggers.