The Genius Tools 5” Air Angle Grinder, No. 505506, has a 1hp-balanced air motor tha provides 12,000 rpm free speed. It also has a front exhaust and a tease throttle. The powerful motor features plenty of power for material removal, metal dressing, rust removal, weld preparations and automotive body work fabrication. The contoured throttle lever provides control for applications ranging from feather edging, to full-speed grinding.