O'Neill Mens 1.5 mm Hyperfreak Long Sleeve Crew Top Neoprene^Nylon^Spandex O'Neill Hyperfreak L/S crew wetsuit jacket. Men's wetsuit jacket. Constructed from O'Neill's 1.5mm TechnoButter neoprene - 20% lighter, 30% less water absorbent, and quick drying. Flatlock seams. Seamless shoulders and underarms.