Stanley J5210H Proto 3/8-inch Drive Socket 5/16-inch - 6 Point Proto 6 Point Sockets are ideal for use on stubborn or damaged fasteners and also on fasteners made from soft materials. The Torque Plus design is a high performance drive configuration which allows for quick and easy socket engagement to the fastener flats, not the corners. The Torque Plus configuration employs a radius-corner design, shifting contact area and stress away from the fastener corners and distributing contact stresses over a large area of the socket, minimizing slippage. The Torque Plus internal design minimizes fastener rounding, helps to extend fastener life and allows the user to more easily turn worn, rounded, or rusted fasteners.