After thousands of rounds, your AR-15's stock pins can eat away at the trigger and hammer pin holes. Worst case scenario, pins can walk themselves loose while you're firing. RISE ArmamentA(R) Anti-Walk Pins kep the trigger and hammer pins from rotation and wobble. Includes a standard .154 pin Includes a .1555 pin for worn receiver trigger and hammer pin holes Backed by RISE Armament's lifetime manufacturing warranty Order today!