Welcome to Palmetto State Armory!
These are the Generation 2 Mod 2 pin sets. They are the STRONGEST pins that can be produced and were designed to withstand the high impact of full and semi-automatic 9mm and .223 suppressed weapons.
The pins are stainless steel pins. End retainers are black oxide, dark earth, or OD green. 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.