Be ready with the right tools for the job. The Brownells BRN-4 / HK416 Combo Wrench was designed as an all-in-one wrench to perform most disassembly and reassembly tasks with ease. Integrated castle nut, barrel nut, and flash hider tools are combined with a A 1/2" drive ratchet for using a torque wrench such as our Brownells Torque Wrench, item number 018150050. Our combo wrench is specifically designed to be compatible with our line of BRN-4 Uppers, Lowers, and Barrels, most generations of HK416's, and Giessele barrel nuts and handguards. Combo Wrench features: Castle Nut Tool Barrel Nut Tool Flash Hider Tool Bottle Opener ½ Mfg: Brownells