Made in the USA. These 20KV Super Dielectric Overshoes are made from an ozone resistant yellow rubber. The deep heel provides extra safety when climbing ladders and poles. These overshoes are 100% waterproof with a fabric lining. The sole is an anti-skid bar tread. The outsole of these overshoes and boots have been tested to meet the electric hazard requirements of ASTM F2413. Fitting tip for Super Dielectrics: Standard sole, order one full size larger than the boots to go over. Heavy lug sole, order two sizes larger than the boots to go over.