Stahlwille STW494 INHEX Socket 3/8in Drive 4mm Stahlwille Series 49 INHEX Sockets have a 3/8in Square Drive and are suitable for socket head/hex head screws. Made from chrome alloy steel and chrome plated. Manufactured to DIN 7422 standards. Overall Length: 52mm. Metric sizes. Made in Germany. Stahlwille INHEX Socket 3/8in Drive. Size: 4mm.