Developed with versatility in mind, the Arctic Outpost series delivers all of the protection and comfort Muck Boot are known for. Features include 5mm CR Flex-Foam, Fleece Lining, a New EVA Midsole, and an Aggressive traction Outsole. The upper is made of Flex Foam, the lining is Fleece, and the sole is EVA. Care instructions: Clean with cold water and use rubber boot care. Heel Height: 5.0 cm. These are versatile, lightweight, and comfortable wellington boots with an inner textile lining and a waterproof and durable outsole.