These are the Generation 2 pin sets. These are the STRONGEST pins that can be produced and were designed to withstand the high impact of full and semi-auto 9mm, .223, and 7.62mm suppressed weapons. The pins are black nitrided stainless steel. End retainers are black Nitride, dark earth, or OD green. The dark earth and OD green have a phosphate base coat. An absolute must-have for all M-16 owners. They will also protect your AR-15. Special anti-creep retainers prevent wear on your irreplaceable M-16 or AR-15 receiver. Pin installation tool & 2 TORX wrenches & screws included. No modification to firearm required. THE TORQUE SPEC ON THE SCREW IS 11 inch/lbs. MAXIMUM. We recommend 8INCH/LBS of torque.