The Sirrus is designed specifically for women & has been enhanced for this season with cleaner looks & enhanced ventilation. The key to the load carrying comfort & stability is the Airspeed mesh back panel. A lightwire frame effectively transfers weight to the hip belt whilst the sprung mesh panel keeps the pack away from your back allowing full ventilation when in use. The ergonomically shaped shoulder straps & the hip belt are made with Spacermesh foam, a stable & comfortable EVA with cut-outs to allow air flow. Access to the main compartment is through a zipped front panel allowing easy access to the bags contents. You get all the usual & useful Osprey features with this pack such as the internal hydration sleeve, zipped hip belt pockets, stretch side pockets, integrated & detachable raincover & the brilliant Stow-on-the-go trekking pole attachment system. You can safely stash your trekking poles away when they are no longer required without having to remove the pack or pestering a mate to do it for you. The new womens Sirrus sets the benchmark for ventilated hiking packs. Air Speed trampoline suspended mesh backsystem Sternum strap with emergency whistle Stretch mesh side pockets with Inside Out compression Zipped front panel access Twin zippered hip belt pockets Stow-on-the-Go trekking pole attachment Integrated & detachable raincover External zipped pocket External zipped soft lined tech pocket Internal hydration sleeve Internal key attachment clip Removable sleeping pad straps Side compression straps Single ice axe loop