NcStar's AR15 Armorer's Barrel Wrench is a generation 2 combo tool with many tools to work and upgrade your AR-15, M4 and M16. It features a barrel wrench for GI Barrel Nut, free-float barrel nuts with GI spacing, DD barrel nuts and YHM ( 1 3/4") Spanner wrench, A2 (3/4") and 5/8 Flash Suppressor wrench, M4 Collapsible stock castle nut wrench, A2 buffer tube wrench, a flat blade screw driver for A2 buttstock plate, 1/2" and 3/8" drive compatible, lower receiver push pin tool and 1/4" hex bit drive socket, 1911 barrel bushing wrench, with a tactical bottle opener. All tools are clearly labeled.