High Sierra Piranha Hydration Pack 100% Nylon Imported Add-A-Bag attachment loops for securing the pack to a larger bag 2-liter Quench Hydration System has a wide opening reservoir for easy filling and cleaning. System is BPA free and antimicrobial. Insulated Thermo-Sleeve hose cover prevents water from freezing in the tube. Elastic loops for convenient hydration hose positioning. Large, front-load main compartment holds gear. Organizer with key fob holds bicycle tools, accessories. Stretch-mesh front pocket for external storage. Airflow back panel helps channel moisture. Lightweight shoulder straps with adjustable sternum strap. Side compression straps stabilize loads. Tuck-away mesh sport flap holds a helmet. Removable waist belt allows the bag to be customized for each activity. Reflective loop holds bike LED blinker.