Neiko 30109B Mini Angle Die Grinder Rear Exhaust, 90 Degree | 1/4" Collet | Self Locking Safety Lever | 90 PSI, 20000 RPM 20,000 RPM free speed pistol grip rotary tool with 1/4" collet accepts a variety of heads for weld prep, grinding, polishing and more Air grinder uses a standard 1/4-inch NPT air inlet and 3/8" (ID) hose, can be powered by a standard air compressor at 2.1 CFM (90 PSI) Built-in air regulator can be adjusted with flathead screwdriver or included wrench; Paddle lever throttle allows feathering control Made for precision, rear exhaust air flow system directs air away from work surface and composite housing reduces effects of chill and vibration Hand-held air die grinder with compact right angle design for flexibility in tight spaces and weighs in at only 1lb 3oz for minimal user fatigue