The Katari 1. 5L Backpack is one of the lowest-profile packs Osprey makes, and provides a way to stay hydrated on your ride without loading yourself down with unnecessary space and gear. The 1. 5L capacity is just enough space for the included Osprey Hydraulics LT 1. 5L reservoir, which stays in place thanks to the structure provided by the Atilon foam framesheet. An AirScape backpanel allows air to flow between you and the pack while a BioStretch harness offers a bounce-free ride by conforming to your shoulders. Small but handy features include a magnetic sternum strap that keeps your bite valve accessible and a tail light loop that helps you stay safe when the sun sets.