TacFire Official Multi-Caliber Magic Armorer wrench tool is made of Hardened Steel with 4140 Powder coated Finish. This combo wrench will take care of your .223 and .308 Free Float barrel nuts, Jam nuts, Flash hiders, and the slot feature is used as a torque wrench. Note: It will not work for LR308DPMS. This is not compatible with your standard barrel nut, this is for the installation of Free Floating Hand Guards Only.