Armstrong Drive Socket, Deep Length, Measurement System Metric, 3/8 in Drive, Square Drive, 12 Point Socket, 20 mm Socket, 2.512 in Overall Length, 1.13 in Drive End Width, 1.13 in Socket End Width, 0.693 in Bolt Clearance Depth, 1-1/2 in Opening Depth, Ball Locking, High Alloy Steel, Chrome Plated