This Zentherm Skiff Suit features 2.5mm thermal protection technology, 4-way stretch, and a 5000% stretch rating. Partial neoprene construction: 2.5mm limestone neoprene, GlideSkin neck seal, quick-drying, water-repellent lining, and internally taped for invisible seams. Next-to-skin construction: 90% neoprene, 10% nylon. You can watch a video about the Zentherm series here: https://www.gill.jp/movie/ZenthermWithAudio.mp4. Please note that sizes may differ from those in Japan, so please check carefully before ordering. For more information on sizes, please see here: http://gill.jp/size-guide/