Rock Fall Zinc Conductive Safety Trainers100% Non Metallic and conductive, with protective toecap and midsole, Zinc is a conductive trainer developed with specialist comfort materials that are certified to have close to zero electrical resistance, making them conductive in accordance with EN ISO 20344: 2011 and ASTM F2412 18 test methods, including a conductive, shock absorbing dual density EPR rubber outsole and Activ Step conductive comfort footbed.