PROTO® Black oxide finish deep impact socket set. Sockets are ideal for use on stubborn or damaged fasteners and also on fasteners made from soft materials. The TORQUEPLUS™ design is a high performance drive configuration which allows for quick and easy socket engagement to the fastener flats, not the corners. The TORQUEPLUS™ 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 TORQUEPLUS™ internal design minimizes fastener rounding, helps to extend fastener life and allows the user to more easily turn worn, rounded or rusted fasteners. Impact sockets 19 piece, 1/2 inch drive socket clip and 9, 17 inch socket bar. ASME B107.2.