Extra-heavy duty armorers wrench provides easier installation and removal of all barrels up to 1A 1/4" diameter with either encapsulated or peg-style barrel nuts. Extra-long handle features smooth, contoured edges for comfortable use. Includes A 1/2" square drive opening for torque wrench application; 5/8" and A 3/4" slots fit receiver extensions and A1/A2 flash suppressors applications, .308 for use with AR-Style .308 rifles. 3/4 inch slot may not fit some brakes, flash hiders or comps with less than .410 long driving flats. Will NOT work with DPMS 20 tooth pattern .308 barrel nuts. Mfg: Smith Enterprise SPECS: 17-4 stainless steel, black oxide finish. 12" (30cm) long, 1" (2.5cm) wide handle. .400 thick.