Designed to take on extreme environments, these 400G insulated, waterproof work boots keep you comfortable in any weather. The KEEN.POLAR TRACTION in the outsole gives you reliable stability even in variable winter conditions. Features: Left and right asymmetrical composite toes KEEN.Dry waterproof, breathable membrane 400g KEEN.Warm insulation 100% non-metallic construction TPU shank for midfoot support 90 degree heel Cleansport NXT for natural odor control Meets ASTM F1677-96 MARK II non-slip testing standards Meets ASTM F2412-11 and F2413-11 M I/75 C/75 EH standards