Straight Die Grinder, 1/4 in NPT Female Air Inlet, 1/4 in Collet, Medium Duty, 25, 000 RPM, 0.5 hpMfr # MP4458 Item Die Grinder Air Inlet 1 4 in NPT Female Collet 1 4 in Duty Medium Duty Free Speed 25,000 RPM Grinder Type Straight Handle Material Steel HP 0. 5 hp Includes Collet Wrenches Required Pressure 90 psi Throttle Safety Lever Variable Speed No CFM @ Full Load 23. 0 Average CFM @ 15 Second Run Time 5. 75 Exhaust Front Characteristics 200 Series Collet Bearing Type Double Shielded Ball Grinder Orientation Straight Tool Weight 1. 3 lb Max.