Designed for treks of three days or more, the Osprey Sirrus 44 hiking backpack is a practical, sturdy and spacious women's model. It offers 44 liters of volume and neat accessorizing that includes a removable mat or sleeping bag strap, an ice axe loop, a front expansion pocket, Stow-on-the-Go pole holders and a pocket compatible with Hydraulics and Hydraulics HT hydration systems. The padded waistband helps distribute the load for comfort and the chest strap includes an emergency whistle. A rain cover is included with this model, for effective protection of your gear in inclement weather.