IRWIN 1877497 Impact Performance Series Deep Well Square Drive Socket Extender, 3/8-Inch Drive, 3-Piece Built for maximum durability and long life with impact drivers Made from heavy-duty chrome molybdenum steel for maximum durability and long life with impact drivers Black oxide finish resists corrosion and increases life Connects 3/8" square drive drills or accessories to 3/8" square drive sockets or accessories Manufactured with heavy-duty, cold-forged, high-grade steel to withstand high torque output