Ingersoll-Rand Model 211 3/8" Super Duty Air Impact Wrench.
The most powerful 3/8" palm-grip wrench you can get, with all the built-in advantages of the Single Hammer Mechanism, Pressure-Feed Lubrication System, and Power Regulator. It packs plenty of extra power to handle bolts up to 7/16" for oil pan removal, exhaust system work, transmission and bench work.
Up to 150 ft.-lbs. torque.
A sleek, in-line palm-grip design.
Steel hammer case protects the hammer mechanism against punishing use.
Free speed: 10,000 RPM;
Max torque: 150 ft.-lbs.;
Avg air consumption: 2.5CFM.