STEELMAN 102-4 1/2-Inch Heavy-Duty Impact Wrench with 2-Inch Anvil Twin Hammer TWIN HAMMER DESIGN - Twin hammer mechanism delivers smooth and balanced yet hard-hitting blows VARIABLE SPEED TRIGGER - Variable speed tease trigger gives optimum control of speed EXTENDED ANVIL - 2-Inch extended anvil allows use of flip sockets and easier access to deep tire wells EFFICIENT MOTOR - Premium efficiency air motor uses only 4 cfm of compressed air so you can work longer PEAK TORQUE - 400 ft-lb of available maximum torque FREE SPEED - Free running speed is 7,000 RPM STEEL HAMMER CASE - Steel hammer casing protects the hammer mechanism during heavy duty applications NPT INLET -1/4-inch NPT threaded inlet for use with standard 3/8-inch diameter compressed air lines