This is the Akona Unisex Skin Suit Front Zip UV Protective Dive Suit Features: 2nd layer of thermal protection under your wetsuit Assists in donning your 3, 5, or 7mm suit. No more neoprene sticking to your skin. UV protection (SPF50) Defend against sea lice, jellies, and other irritants Form fitting to reduce drag Full-front zipper closure Thumb loops and stirrups prevent suit riding up when worn under a wetsuit The Akona Unisex Front Zipper Skin Suit provides warm or cold-water protections. A wetsuit works when a thin layer of water is trapped between the wetsuit and the skin. The body temperature of the diver heats this water creating a nice insulation from the colder surrounding water. A properly fitting wetsuit directly relates to the effectiveness of the insulation. Your wetsuit should fit snug and still allow a full range of motion.