The flexible frame suspension system provides comfort and torsion with movement, while still allowing the backpack to compress and pack away into the included mesh stuff sack for travel. Weighing in at just 595 grams, this fully equipped apline pack is capable without sacrifice. Features 18 liter capacity Flexible frame that moves with your body Removable hip belt Sternum strap, detachable Wrap around zipper on main compartment Hydration compatible Gear loops for hiking poles or ice axes Hypalon™ reinforced external daisy chain Water bottle pockets Two internal pockets and key loop for securing small items Padded, breathable mesh shoulder straps and back panel Compression storage sack for travel Specifications Volume: 18 liters Weight: 1lb 5oz (595g) Unpacked Dimensions: 10 x 20 x 6.5in (25.5 x 50.8 x 16.5cm) Packed Dimensions: 9 x 9 x 3.5in (22.9 x 22.9 x 8.9cm) Materials 210D Robic® high tenacity nylon, UTS coated, DWR finish 100D bluedesign nylon, PU coated, DWR finish YKK® zippers and hardware EVA foam padded back, shoulder straps, and hip belt Bartak reinforced construction Coating Specs UTS coating: adds waterproofing with up to 30% increased tear strength over traditional coatings PU coating (polyurethane): durable waterproofing