Professionals who want the best choose this tool for front end work, heavy exhaust work, riveting, king pin removal, bushing driving and bolt shearing. Extra-sensitive tease throttle controls starting strokes. Longer stroke piston. .401� shank opening, 1,725 blows par minute at 90 psi, 9/16� bore diameter, 4� stroke length, 8.5� tool length, 3 CFM average air consumption, 11 CFM actual air consumption at load, 1/4� NPT (F) air inlet and 5/16� minimum hose size.