LBE Unlimited Armorers Tool, For AR-15, 4140 Steel Construction, Black ARMTL The LBE AR-15 Armorers tool is made in the USA from heat treated 4140 steel. The wrench features aid in the installation and removal of castle nuts" 3/4" muzzle brakes" A2 receiver extensions" take down/pivot pins" standard barrel nuts and free float barrel nuts. Featuring a 1/2" torque wrench and a handy bottle opener" this Armorers wrench will be your go to tool for all your building needs.