Steelman High-Speed Sander has a variable wheel size to fit 3" to 5.5" pads, with a spindle thread of 7/16"-20 and a free speed of 18,000 RPM. This air-powered tool features a lightweight design for easy handling and a built-in regulator and variable-speed throttle for precise speed control, as well as a rugged, energy-efficient 0.5 HP motor. This unit also features a 1/4" air inlet (for 3/8" hose) and runs on 90 PSI of air pressure, with an air consumption of 4 CFM, measuring 7-1/2" in overall length.