The  O'Neill Psycho One 4/3 mens wetsuit is and incredibly stretchy and warm wetsuit in the O'Neill range. The patented Z.E.N. zip closure (that's the system O'Neill use for the zip on the back) minimises flush. The 4mm wetsuit for men comes with minimal seam design and the seams feature fluid weld making the suit super comfortable and warm. It's made from Technobutter 3 neoprene, O'Neill's top of the range material that we have come to love so much.   Key Features: Patented Z.E.N. Zip Closure Minimal Seam Design Anti-Flush Barier Double Super Seal Neck Construction: Fluid Seam Weld Full Body: Technobutter 3