Oneill Psycho II Zen Zip 3/2mm FSW Wetsuit Mens 3843 Oneill Psycho II Zen-Zip 3/2mm FSW Wetsuit is on the rampage, destroying all imitators that try to cramp its style. The O'Neill Psycho 2 is comprised of UltraFlex XDS neoprene, meaning it's lighter, more flexible, and warmer than ever before, and an X-Type/X-Foam firewall on the chest and back go above and beyond too keep away the cold. Ergonomic D-Tox knee pads are super comfortable and protective, and a 2X Fluid Seam Weld keeps you from chaffing and keeps the water out