Stanley Proto J5217M 3/8-Inch Drive Socket, 17mm, 12 Point Proto 12 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 The Torque Plus configuration employs a radius-corner design, shifting contact area and stress away from the fastener corners The Torque Plus internal design minimizes fastener rounding, helps to extend fastener life