Brilliant! A lightweight backpack that feels like a running vest but with enough room for an overnighter. The large 40L capacity can accommodate all your camping equipment without carrying a heavy backpack. You can access important items like your phone and water easily from the front pockets and it allows for much better freedom of movement for fast moving along the trail. With it's new Infiknit™ and FastFlow technology it breaths and wicks well, adding to the comfort and it has plenty of dedicated external storage, a roll-top opening and a full-side external zipper for easy access to anything inside. 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 SPECS 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