Arc'teryx Men's Gamma Lightweight Hoody Void Pin on SCOTTDOGGAMING. The Gamma Lightweight Hoody is a functional softshell courtesy of Arcteryxbuilt to the exceptionally high standards youd expect from the Canadian outerwear masters. Made from a woven blend of nylon and elastane known as Fortius DW 2. 0, its breathable, wind resistant and water resistant. That four way stretch keeps it comfortable too, while while that patented StormHood keeps the elements at bay, even over a climbing helmet.