Arc'teryx has earned a reputation in the outdoor industry for making some of the toughest gear available. Arc'teryx doesn't pull any punches when it designs its gear. Nowhere is this more evident than its SV line of clothing--the burliest clothing that Arc'teryx makes. For 2013, Arc'teryx redesigned its venerable Alpha SV Jacket around a high-density nylon face fabric with a Gore-Tex Pro 3L laminate to make it just as tough as before, but now quieter and more supple. To earn the Arc'teryx SV (severe weather) moniker, the Alpha SV jacket had to be tough. And, of course, this is Arc'teryx, so when we say tough, we mean bulletproof. The jacket's main body fabric is N80p-Gore-Tex Pro 3-layer. N80p is a high-density nylon weave. The high-density construction minimizes the yarns' exposure to abrasion, which reduces damage to filaments to maintain surface integrity. A durable micro-grid woven backer reduces weight and further resists abrasion. What all that means is years of guaranteed waterproof breathable service, even in the harshest conditions. The Alpha SV is more than tough fabric, however. It's designed to work in perfect harmony with climbing harnesses and backpacks. This means the chest vent pockets and underarm zipper vents are designed out of the way of waist belts and shoulder straps, and the removable HemLock inserts keep the jacket in position when worn underneath a climbing harness. The hood and underarm zippers are designed for one-hand use for easy operation in tight spots. Of course, the Alpha SV is equipped with stormproof zippers throughout.