Rear exhaust directs air away from work Built-in regulator Safety lever throttle for positive speed control Ball bearing construction for long life Free Speed (RPM) @ 90PSI: 22,000 Collet Size (In.): 1/4 Air Inlet (NPT): 1/4 Min. Hose Size (I.D.): 3/8 Recommended Air Pressure (PSI): 90 Average Air Consumption (CFM): 4 Sound Level (dBA): 93 Length (In.): 7 Shipping Weight (Lbs.): 1.25