FPX-320 FPXair Right Angle Die Grinder, 1/4" Air Inlet, 2200 RPMPneumatic Power Tools: This angle die grinder gives you more control and precision as you grind, sand, and polish on a variety of materials Durable Air Tool: Grinder tool operates at 20,000 RPMs and the 1 2 HP motor provides plenty of power to reduce stalls; precision 3 pc collet keeps the bit secure under extreme loads Quality: Durable construction and precision bearings reduce vibration and spindle run out; the safety lock out throttle lever helps