The Piranha 10L features Add-A-Bag attachment loops for securing the pack to a larger bag, an insulated hose cover to prevent water from freezing in the tube, a large front-load main compartment to hold gear, an organizer with key fob to hold bicycle tools, a stretch-mesh front pocket for external storage, an AIRFLOW back panel to help channel moisture, lightweight shoulder straps with adjustable sternum strap, and side compression straps with webbing keepers to stabilize loads. The tuck-away mesh sport flap holds a helmet. The removable waist belt allows the bag to be customized for each activity. A reflective loop holds a bike LED blinker. The 2-liter/67.6 ounce hydration system has a wide opening reservoir for easy filling and cleaning. This system is BPA-free and antimicrobial.