3-7/8" 6 point locknut socket. Wheel bearing locknuts are easy to remove or install with these specially designed sockets. Sockets are made of high-strength steel; openings resist "rounding out". Can be used with an extension and torque wrench to tighten the locknut as required This socket has a 3/4" square drive opening, permitting the use of an extension and torque wrench to tighten the locknut as required. Locknut removal and installation is simple, even when wide-rim wheels are involved, since a long extension may be attached to the socket to provide the necessary clearance.