AKONA 3.5mm Titanium Deluxe Molded Sole Hard Scuba Diving Dive Boots with Zipper, Heel and Toe Cap 3.5mm Akona Titanium Deluxe Molded Sole Hard Scuba Diving Dive Boots with Zipper, Heel and Toe Cap Constructed of 3.5MM nylon II neoprene for warmth This creates a more comfortable and warmer boot All edges finished with black nylon binding