Chicago Pneumatic CP734H Cp 1/2 In. Drive Heavy Duty Air Impact Wrench. Working torque: 25-310 ft./lbs.; maximum torque: 425 ft./lbs.; blows per minute: 1020; free speed: 8400 RPM; average air consumption: 3.75 cfm; air inlet thread: 1/4" NPTF; minimum hose size: 3/8"; sound dBA: 93; length: 7.5", weight: 5.13 lbs.