A Favorite For Moving Fast And Light In The Backcountry This lightweight Fastpack has an optimal weight-to-capacity ratio for longer adventures over rugged terrain so you can move fast in the backcountry. True to our roots, it uniquely fits like a vest with water bottles up front, but distributes weight like a pack. We gave it an upgrade with Infiknit and FastFlow technology to increase the backpanel's breathability and moisture wicking. This do-it-all pack also has plenty of dedicated external storage, a roll-top opening and a full-side external zipper for easy access to anything inside. Infiknit + Fastflow: Back panel combines Infiknit seamless harness technology with Fastflow breathability for a comfortable, anti-chafe harness Full Side Zipper: Easily and quickly access gear anywhere inside the fastpack with the full, external side zipper Quick Access To Water & Nutrition: Pocketing on the front harness straps stores water bottles, snacks and your phone for quick access to the essentials Trekking Pole Attachment: Securely stores trekking poles between uses Features: Large front storage for water, phone, maps, glasses, or food Two large side pockets for larger water vessels Unique zip-down main compartment for total access to gear Roll-top closure expands or compresses to secure varying capacities Large external stretch mesh pockets for quick access Sliding rail sternum straps Removable and height-adjustable T-hook waistbelt for heavier loads Easy access pocket with keyfob MonoRip Mesh is very strong, but extremely breathable. Daisy chains for securing extra gear Specifications: Volume: 2502 in3 / 41.0L Dimensions: 19.5" x 11" x 7.75" / 49.5 x 27.9 x 19.7 cm Weight: 1.60 lbs. / 0.715 kg No. of Exterior Pockets: 15 Reflectivity: Yes Reservoir Compatibile: Yes User Chest Size (S/M): 25 - 40" / 64 - 102 cm User Chest Size (M/L): 30 - 48" / 76 - 122 cm Materials: Primary/Body: 100% polyester Ultimate Direction Fastpack 40L Backpack