This is the XS Scuba 6.5mm Deluxe Zipper Boots Scuba Diving Booties Features: Aggressive "SureGrip" sole Coldwater zipper dam Extended toe protector Protective heel cap Glued and double blind-stiched Nylon zipper stop Nylon edge binding Whether you are diving in the tropics or off of the northern California coastline, the Deluxe zippered boot accommodates every diver for almost every climate. Available in three different thicknesses (3, 5 & 6.5mm), paired with deluxe features as the reinforced heel and toe cap and the double blind stitched seams, the deluxe zippered boot is sure to keep you warm while giving you a rugged boot for all your diving excursions."