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. 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 firearm 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.
The only difference from the Gen 2 pin kit is the appearance of the sideplates. There is no strength difference.
PLEASE READ the INSTRUCTIONS!!! Over-torquing the screws can casue damge to these sideplates