The essential Quickstart 2.0 3 Liter Hydration Pack is designed for short to moderate trail running & hiking. Fit & Design: Unisex One size fits most Adjustable sternum straps Moisture wicking stretch woven fabric with chafe free binding materials Breathable mesh shoulder straps 1.5 L Hydration Bladder Included One main zipper pocket on the back Bottle pocket on the front for additional hydration Zippered phone pocket on the front Reflective hits for 360 degree visibility Storage Capacity: 183 cu in/3 L