Armstrong Drive Socket, Standard Length, Measurement System Metric, 1/2 in Drive, Square Drive, 6 Point Socket, 16 mm Socket, 1.457 in Overall Length, 0.87 in Drive End Width, 0.87 in Socket End Width, 1/2 in Bolt Clearance Depth, 0.449 in Opening Depth, Ball Locking, High Alloy Steel, Chrome Plated