MAXIMUM COMFORTMoisture wicking stretch woven fabric & chafe free binding materials plus, breathable mesh shoulder straps.SECURE FITAdjustable sternum straps.EXTRA STORAGE TO GOAmple pockets for all the essentials. Details 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 with additional smaller pocket Bottle pocket on the front for additional hydration Zippered phone pocket on the front Reflective hits for 360 degree visibility 60% Nylon, 40% Polyester Storage Capacity: 244 cu in/4 L Wash & Care Easy to love and easier to care for. Hand wash only - Nathan Power Wash recommended. To clean bladder remove tubing, rinse tubing and bite valve. Turn bladder inside out rinse dry standing up. WHY YOU'LL LOVE IT The essential Quickstart 2.0 4 Liter Hydration Pack with one main back & one small storage pocket at back designed for the short to moderate road and trail running & hiking.