The rubber is reinforced in both the heel and toe area, with a steel shank for additional support . 5mm neoprene bootie make these boots lightweight, flexible and 100percent waterproof. Easy Clean Rubber Waterproof 16'' Work Wellingtons Steel Shank For Arch Support Stretch Fit Calf For Insulation Reinforced Upper And Heel Available In Black Or Moss *From the manufacturer's description