Astro 1757 Air Spot Drill, 500 RPM with 5.5-Inch Deep Clamp Kit and 4 Drill Bits Specifications: Drill Bit Size Chuck Cap.: 5/16-Inch, Free Speed: 500rpm Overall Length: 8-3/4-Inch (222mm), Air Inlet Thread NPT: -Inch Air Hose I.D. Size: 3/8-Inch (10mm) Avg. Air Consumption.: 4cfm Air Pressure: 90-120psi