Fox Head Portage Hydration Pack Eva molded back panel provides added comfort and ventilation while being lightweight and supportive Lightweight mesh shoulder straps allow for ultimate breathability and airflow. Sternum strap allows for stability and support during active pursuits Stowable stretch mesh helmet holder allows for trail helmet to be secured and kept out of the way before or after a ride Wide opening on the hydra valve allows for easy water flow and a comfortable bite valve Hydrapak 3l reservoir