The 3/4" Drive 250 ft-lb HD Torque Extension is designed to prevent damage to wheels, studs, and brake rotors by reducing the risk of overtightening lug nuts which can result in sheared stud bolts, rounded lug nuts, and warped rotors. When used with an electric or pneumatic impact wrench, it limits the effective output of the wrench to 250 ft-lb of torque and anything above that will cause the extension to flex and absorb the extra impact. It is made of resilient chrome molybdenum steel with a red powder coat for additional corrosion resistance.