Carry less water and filter on the fly. Building on the innovative PackFlask™ design, this enhanced system features an integrated filter for fast, reliable hydration on the trail. Simply find a water source, fill and drink directly through the high-flow, self-sealing nozzle. The filter screws securely onto the flask, doubling as a squeeze filter for filling bottles or pots at camp. The stretch-mesh pouch securely attaches to your pack harness for hands-free use.