The Alpine Pack series delivers a high level of water resistance while allowing quick and easy access to pack contents with the Roll-Up Closure System and Aqua Barrier Sack. This 40L pack is constructed with high-quality nylon ripstop and a long list of features to provide versatile performance at a light weight while on multiday backpacking trips and winter mountaineering missions. The top lid conveniently converts into a waist or sling pack when needed.