•Hexagonal, manually operated With square drive as per DIN 3120 - C 12. 5, ISO 1174 GEDORE vanadium steel 31CrV3 Protective insulation up to 1000 V, according to EN 60900/IEC 60900, 2-fold Check-Tool insulation 16 - 18 mm insulation overhang The diameter d1 for the dimensions 27, 30 and 32 is not standardized