Mark Brown Custom AR-15/M16 Gas Tube Gauge

CNC machined, mechanical "No-Go" gauge tells you instantly if your gas tube is out of spec and needs replacement. Simply insert into the gas tube to check for flat spots, dents, kinks, and loss of concentricity. Perfect for armorers, competition shooters and others looking for the most accurate, reliable way to check for tube damage and maintain optimum rifle function. Each gauge is precision ground to exact tolerances. Works on all AR-15, M16, and AR-style .308 rifles. Mfg: Mark Brown Custom SPECS: Steel, black, matte finish. 8A 3/4" (22.2cm) long.