TacFire's AR15 Anti-Walk/anti-rotation pin set features hammer and trigger pins which are used to help keep the hammer and trigger pins securely in place, and protects your receiver from excessive wear and tear. It includes two (2) pins, (4) four screws, two (2) wrenches and one (1) guide cone. Anti walk pin set for Ar-15/M4 style rifles. Keeps trigger/hammer pins from walking out of the receiver Helps prevent wear and enlargement of the receiver trigger/hammer pin holes Made in the USA