With square drive according to DIN 3120 - C 12.5, ISO 1174, with ball groove, Tip GEDORE vanadium special steel, VDE insulation up to 1000 V, acc. to EN 60900/IEC 60900, two-ply Check-Tool insulation, Sockets can only be combined with VDE 1989 T, VDE 1991, VDE 1993 U and VDE 4507, These inserts can only be combined with No. VDE 1991, VDE 1993 U, VDE 1990, VDE 4508-05