Ultrawarmth Boots feature Ultrawarmth Celliant Infrared Thermal Technology embedded in the inner fabric. Celliant is scientifically proven and FDA-determined to conserve body heat and accelerate thermal recovery. These easy-entry boots restrict water flow, protect feet from sharp objects and prevent fin blistering. Its heavy-duty sole has been tested in the wettest conditions to ensure support while walking on wet surfaces like boat floors, to and from dive sites, or when shore diving. With a heavy-duty zipper and wide gusset and ELASTEK full-stretch neoprene around the ankles and calves they fit all variations of lower leg shapes and sizes. Ultrawarmth Boots are available in multiple thicknesses and styles, complementing any wet diving system