These are the Generation 2 Mod 2 pin sets by KNS Precision INC. 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. They will also fit the .308 AR rifles.

The pins are black nitrided stainless steel. End retainers are Black. 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 .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.

IMPORTANT NOTE: The external width of some AR receivers may vary in the trigger/hammer pin area depending on the manufacturer. The pins being too long will not affect the function or performance.
The .170 size fits large pin Colts.