We stay prepared throughout our hike with the Osprey Women's Mira 32L Hydration Pack on our back. It includes a 2. 5-liter reservoir to satiate our thirst when we're hiking for hours and an Anti-Gravity suspension system that uses a combination of different design elements including a LightWire frame mesh back panel BioStretch shoulder harness and AG hip belt to distribute weight enhance breathability and achieve a comfortable fit no matter how far we roam.