The outsoles of the GB00103 10" Carbo-Tec Pull-On Waterproof Work Boot start with real rubber, which is one of the most durable, longest lasting materials in outsole construction. Next, a rare blend of proprietary materials is added to give Carbo-Tec soles chemical and oil resistance. This compound makes the boot highly Oil and slip-resistant. The result is an extremely long wearing, non-marking outsole that is flexible and most importantly, comfortable. This boot is equipped with a Comfort Core insole, high-performance mesh lining and a PVC midsole. Georgia waterproof system Fiberglass shank Goodyear welt construction Non-metallic.