Rockfish, Groundhog Neoprene Welly Boots are again Handmade, 100% waterproof adjustable rear gusset and adjustable calf fastener. 5mm Neoprene Boot, constructed from 4 - way stretch nylon - 100% Waterproof. Rubber Overlay, with 3M Retro Reflective details. Insole engineered to provide comfort all day long. Composite rubber outsole, with EVA midsole, providing a contoured foot bed for long term comfort. Outsole is designed to perform in challenging environments, unique cleat design delivers additional grip.