Horizontal Grinder Heavy Duty Type 1 Free Speed 4500 rpm Wheel Dia 8 In. Spindle Size 5/8 In.-11 4 HP 10.7 Average CFM @ 15 Second Run Time 10.7 CFM @ Full Load Air Inlet 1/2 in NPT Required Pressure 90 psig Min Hose Size 1/2 In. Overall Length 22-13/16 In. Aluminum Handle Material Variable Speed No Side Exhaust Lever Throttle Safety Lock Includes Norton NorZon III Type 1 Reinforced Grinding Wheel