Neoprene Shoes non-corrosive, extremely durable YKK zipper, 6.5mm neoprene, for diving, anatomical ERGO sole and insole, finger/toe/heel protection, high durability, Velcro holds the slider in place, standard neoprene upper, vulcanized rubber sole, flexibility, have a pattern with four seams (2 in front, 2 on the heel)