Air Support Back Panel: Designed with Body Mapping Technology to allow for maximum ventilation on the hottest areas of your back Crux Reservoir: 85oz capacity delivers more water per sip with ergonomic handle for easy refills Removable Waist Strap: Added stability when you need it Secure Phone Pocket: Conveniently located with a zipper closure for secured quick access Trekking Pole Carry: Easily remove or replace poles while running