Armstrong Drive Socket, Standard Length, Measurement System Imperial, 3/8 in Drive, Square Drive, 12 Point Socket, 7/16 in Socket, 0.872 in Overall Length, 0.655 in Drive End Width, 0.655 in Socket End Width, 0.281 in Bolt Clearance Depth, 1/4 in Opening Depth, Pin Locking, High Alloy Steel, Black Oxide