Designed for the coldest and most severe of environments, the Flexshell Waterproof is the pac boot you've been looking for. Waterpoof, steel toe, electrical hazard protection, and insulated with 400 grams of patented thermal insulation comes standard on the Flexshell. Built with the SRX Extreme Slip Resistant outsole and all of the ERGO comfort features so that you're not only dry and warm but also comfortable. ASTM F2413-11 1/75 C/75 Steel Toe. Waterproof Full Grain Leather Upper. Nylon Mesh Lining. Nylex plus EVA Sock Liner. Molded PU Midsole. T1012 Outsole. Cement Construction.