CNC-machined, hammer and trigger pin sets are centerless ground for uniformity and heat treated for durability. Non-Rotating pins come in Standard .154" diameter. Standard-sized pins drop-in and require no modification to the receiver. Redesigned hammer pin and anti-rotation links provide the strongest possible system to eliminate pin rotation, and will withstand the additional force exerted by 9mm conversions and suppressed .223 upper receivers. Helps prevent wear to receiver holes, which is especially important for increasingly-valuable M16 and pre-ban receivers. Notched hammer pin locks into slots in the anti-rotation links; trigger is secured with locking screws, and includes lube ports so adequate lubrication reaches the trigger. Anti-rotation links fit on the outside of the receiver to prevent all movement. SPECS: 416 stainless steel pins. .900” (22.8mm) long, .154" (3.9mm) diameter. Set includes (1) hammer pin, (1) trigger pin, (2) screws, (2) anti-rotation links, hex wrenches, and installation tool. Anti-Rotation Links - Steel, Parkerized finish. Retaining Screws - Steel, black oxide finish.