Hyperflex Wetsuits Men's Polyolefin 1.5mm 50/50 S/S ShirtHighly versatile, the 50 50 is a hybrid design that blends the mobility of spandex with the insulating power of mesh skin neoprene. Wear it alone to beat the chill or layer it under a wetsuit to boost core body warmth. Spandex panels under the arms take the strain out of reaching and stretching motions, so the 50 50 is perfect for paddling, diving and a host of other water sports.