Sharkskin Chill-Proof Long Sleeve Shirt by Bare is 100% Chill-Proof Material and is great as a standalone garment and suitable for under a wetsuit. By itself or underneath a long sleeve wetsuit this top provides the ultimate protection from cold and wind. It has a soft neoprene neck seal to help keep wind, water, spray and waves from entering. The long sleeves offer additional protection from the cold and sun and the thumb tabs (loops) assist when pulling a wetsuit on over the top. The long sleeve design provides the best protection for extreme conditions on-or-under the water.Sharkskin Chill-Proof Material is an aquatic specific, windproof 3-layer composite material that has been developed for water sports athletes. The comfortable micro fleece' layer is next to the skin and wicks' moisture and sweat away from the body to help keep you dry. The second middle technical' layer is 100% windproof yet breathes to regulate body temperature while stopping wind chill. The third outer layer is a nylon/Spandex blend for abrasion resistance and 4-way stretch. It is also UV resistant for sun protection and has a durable water repellent finish (DWR) to provide a protective shell that sheds' water. Sharkskin Climate Control Chill-Proof is neutrally buoyant, odor resistant, itch resistant and machine washable. The shirt is black in color and available in multiple sizes.