AR15 Armorer's Barrel Wrench - Generation 2. Combo tool with many New Features/Tools to work and upgrade your AR-15/ M4/ M16. Barrel Wrench for GI Barrel Nut, Free-Float Barrel Nuts with GI spacing, DD Barrel Nuts, and YHM ( 1Â¾") Spanner wrench. A2 (Â¾") and 5/8 Flash Suppressor wrench, M4 Collapsable Stock Castle Nut wrench, A2 Buffer Tube Wrench. Flat Blade Screw Driver for A2 Buttstock Plate, 1/2" and 3/8" Drive Compatible, Lower Receiver Push Pin Tool. 1/4" Hex Bit Drive Socket, 1911 Barrel Bushing Wrench, and a Tactical Bottle Opener. All the Tools are Clearly Labeled. Steel Construction. Length: 13.8". Weight: 13.0 oz.