The RISE Armament Anti Walk Trigger Pins ensure secure installation of your drop-in trigger. They also improve the reliability of your rifle by eliminating the tendency for standard pins to walk out over time. The RISE Anti Walk Trigger Pins set includes all of the following: one trigger pin onehammer pin four screws two Allen wrenches for easy installation. Also the specs are as follows: Pin diameter .154 inches Pin material: Stainless steel