22,000 RPM; Stall resistant 0.75 HP motor; Built-in regulator for added control on the job; Convenient and comfortable throttle lever design; Ergonomic molded handle grip adds comfort and insulation in cold weather; Complete with coaxial rear hose assembly to eliminate blowing of rubber particles/dust in the work area; Short overall tool length of only 8″ improves access in work area; Low noise level; Low air consumption; 3/8″ Precision keyed chuck; Spindle thread 5/16″ x 24