Aqua Lung SolAfx 8mm Men's Scuba Diving Wetsuit - Black/Charcoal - Medium/Large-Long Torso is made of 8mm, four-way stretch Aqua Flex neoprene while the legs and sleeves are made of 7mm Aqua Flex. These are the thicknesses of the base neoprene before the nylon gets added The attached hood not only prevents cold water from entering the neck, it also features Vent G2 technology that allows trapped regulator exhaust bubbles to exit while keeping cold water out The Plasmaloc zipper has tighter tolerances and a unique integrated tooth design that make the zipper more water resistant than most competitors models A water dam covers the neck and shoulders to add another level of thermal protection against any water ingress through the zipper Skin-in gasket seals in the forearms and calves minimize water entry through the sleeves and legs