hexagon socket wrench hand operated with square drive according to din 3120 c 12 5 iso 1174 gedore vanadium steel 31cr v3 with vde insulation as per din en 60900 two ply check tool insulation not suited for use with vde 1991 10 12 mm insulation overhang must be added to the lengths stated sizes 27 30 and 32 diameter d1 is not standardised