From the Manufacturer The CP7556ES is a powerful Extended Die Grinder with an Insulated Handle Grip. Powerful .25 HP Motor with 28,000 RPM of Maximum Speed. Also features Easy Access Speed Regulator, Rear Exhaust and lock off throttle.3.5 Inch Extended shaft. Collet size: 1/4; average air consumption: 6 cfm; air inlet thread: 1/4-Inch; minimum hose size: 1/4-Inch; length: 9.8-Inch; weight: 1.5 lb.