The key to the Atmos superb comfort & ventilation is the Osprey 3D tensioned & adjustable Air Speed mesh back panel. This panel provides support & stability when under load yet maintains an air gap from your back to allow maximum ventilation. Torso length can be adjusted by simply un-Velcroing the shoulder harness to give you about 8cm of adjustment. To further increase ventilation the shoulder straps feature perforated foam padding & mesh fabrics. The Fit-On-The-Fly hip belt is, as the name suggest, is fully adjustable even when wearing the pack. The padded section of the hip belt can be un-Velcrod to extend the wings to obtain a precise body fit. The top lid is fully adjustable to allow extra carrying capacity & it has a secure zipped pocket with internal key clip. On the front of the pack there is a large stretch stash pocket that is ideal for wet gear such as waterproofs & tent fly, & two large zipped pockets that run the length of the pack. Twin stretch side pockets feature Inside Out compression that enables you to run the compression straps over or under the pockets depending on your needs. To finish off the storage options there are two zipped hip belt pockets. The Atmos 50 is a superb multi-day lightweight backpacking bag with an extremely comfortable & ventilated carrying system. Air Speed trampoline suspended mesh backsystem Sternum strap with emergency whistle Stretch mesh side pockets with Inside Out compression Top lid access Stretch front pocket Twin zippered hip belt pockets Stow-on-the-Go trekking pole attachment Twin ice axe loops Adjustable torso length Fit-on-the-fly adjustable hipbelt Front tie off points Internal hydration sleeve Removable sleeping pad straps Side compression straps Twin zippered easy access front pockets Under lid zipped mesh pocket