These Muck Scrub boots feature stretch-fit topline binding snugs calf to keep warmth in and cold out. Breath- able Airmesh lining. Multi-ribbed tread-designed outsole. Flex-foam bootie with four-way stretch nylon, 100% waterproof, lighweight, flexible and buoy- ant. Seamless, quick-clean rubber overlay. Kick rim for hands-free removal. 1.25 mm semi-rigid rubber reinforcement in the toe, heel, achilles and shank areas.