Rock Fall SURGE BOA RF910 Electrical Hazard Safety Boot SB CI E FO WRU HRO WR SRC 100% non-metallic, with protective toecap and midsole, Surge is developed with specialist durability materials that are certified to withstand electrical risks of 18kV in accordance with the ASTM F2412-18 test method, including FORCE10® components, an Activ-Tex® waterproof membrane and Activ-Step® PU anti-fatigue comfort footbed