The STEELMAN 5 inch High Speed Sander is super lightweight at 2.40 lbs. and that makes it so convenient to work with. The variable throttle allows you to control what speed that you would like to use. This handy Sander has a rugged, energy efficient 0.5 HP Motor. The Specs are as follows: 3 inch-5.5 inch wheel size, 18,000 RPM, 7/16 inch-20 spindle thread, 1/4 inch NPT air inlet thread, 3/8 inch ID air hose size, 90 PSI air pressure, 4 CFM, overall length is 7 1/5 inch and the weight is 2.40 lbs.