s the Bare 5mm Ultrawarmth Boot Scuba Diving Snorkeling Booties Features: Low-loft Celliant infrared inner fabric ELASTEK full-stretch neoprene for ankles and calves Fused cut edges for unrestricted stretch Heavy-duty sole for added durability and stability Heavy-duty zipper with wide gusset for easy entry Durable toe and heel cap Fin tab to prevent strap movement Double-glued and blindstitched to eliminate water entry 5MM neoprene with low-loft Celliant inner fabric ELASTEK neoprene around upper calf with fused-cut edges for comfortable fit SIZE runs about a 1/2-full size Large 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 gussetand ELASTEK full-stretch neoprene around the ankles and calvesthey fit all variations of lower leg shapes and sizes. Ultrawarmth Boots are available in multiple thicknesses and styles, complementing any wet diving system.