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 and .223 suppressed weapons. The pins are stainless steel pins. End retainers are black oxide, dark earth, or OD green. Connectors have phosphate finish. 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 Allen wrenches included. No modification to gun required.
The .1555 dia. pin is for worn receiver trigger and hammer pin holes. Being non-rotational, further wear is eliminated. They will also fit new receivers and will remove the free-play in match triggers. The .1555 will not fit Jewell Trigger System.
The .170 size fits late model Colts.
For Rock River National Match triggers use the .1555 only.
There is no strength difference between the Gen 2 and Gen 2 Mod 2 sideplates. The only difference is cosmetic.