Features and Benefits: This high grade truck wheel bearing locknut is made of high strength steel Socket is designed for use with 3/4 square-drive manual tool only Opening size: 3-13/16 A long extension may be attached to the socket to provide the necessary clearance. Heavy-Duty Truck Wheel Bearing Locknut Socket Features This high-grade truck wheel bearing locknut socket is made of high-strength steel. /> NOTE: Sockets are designed for use with 3/4 in. square-drive manual tools only. Impact tool use voids sockets warranty. /> Opening size (8 pt.) 3-13/16 .