Hex 6mm long key with connection to 3/8" Socket Wrench
1st class quality tool from the German brand Stahlwille.
 
This is one of the most used hex keys in a divers workshop it fits on the DIN inlet fittings of most brands: Scubapro, Apeks, Aqualung, Dive Rite, Mares and manny more.
 
EAN: 4018754003273