Expert base Wheel Safety Helmet with wheel ratchet adjustment size 55-62cm. High-density polypropylene shell helmet, 4 points textile suspension harness.Electrical insulation up to 1000Vac or 1500Vdc (EN 50365). Electrical properties ( 440Vac) .Up to 7 years lifetime from manufacturing date. Standards: EN 397 (-10°C / +50°C, LD, 440V a.c) EN 50365 Class:0   Materials: PP, PE, Woven Webbing, Nylon