14,000 RPM; 1.0 HP motor eliminates "stall" and increases reliability; Extended length for better reach. Get in where other tools fail to go!; Compact tapered gear housing with close-coupled grinding wheel; Reaches inside corners of as little as 30° with 4" wheel; Superior steel grade internal gears for longer life; Spindle lock for easy wheel change; 11 position rotational guard; Grinder disc sizes: 4" (1/16 x 3/8) (1/8 x 3/8)