Drop-In "AR15/10" Fire-Control for .223/5.56 NATO, 300 BLK, .308/7.62 NATO; Enhanced Duty Trigger; "Duplex" Trigger Bow, High or Low Finger Placement; 2 User-Adjustable Trigger Weights of 4+ and 6+ lbs; Single Stage, Semi-Auto; For Standard AR Lower Receivers Using Small Pins of 0.154-inch Diameter; "Hint" of Creep, Slightly Shorter Travel to Break from Moment of Reset; Clean Break, Best-In-Class Fast/Positive Reset; Faster Hammer Lock-Up than Stock, MIL-spec Strike Energy; Heat-Treated Alloy Steels