Steelman Die Grinder includes a 1/4" collet and offers a free speed of 25,000 RPM. This mini air-powered tool features a compact and lightweight design, with a built-in regulator included. 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 4-3/4" in overall length.