Supports the gas cylinder of your M1 Garand rifle and keeps it from rotating when removing the gas plug. Lets you easily separate these parts at home or in the field, without damage. A very small number of gas cylinder/locks have been observed to be slightly larger in diameter than others. A slight adjustment of the gas cylinder wrench using a Dremel, course sandpaper or file may be required. The amount needed to be removed for a perfect fit is generally very minor. Color may vary. Manufactured by Fulton Armory.