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. Effectively removes common waterborne bacteria, such as E.coli (99.999%) and parasitic cysts (99.9999%) per HSF 42.HydraPak Packflask Filter Kit 750ml Features: Stretch Mesh Pouch attaches to your pack harness and securely holds the bottle for hands-free hydration The integrated filter removes Escherichia coli bacteria, Cryptosporidium parvum cysts, and Giardia Lamblia from approximately 1,500 liters of water at a rate of >1L per minute. Sized for easy integration with the pouch, the empty PackFlask™ bottle packs small — just flatten, roll, and stash it away. Dust Cover protects the nozzle from dust, mud, dirty hands and bacteria. Quickly opens and closes with a single-handed flip. Lighter than traditional bottles, and made of durable TPU with RF-welded seams. Plugs into filter valve and threads onto a bottle of clean water for backflushing the filter to restore flow rate. Filtration: Avoid freezing filter. Freezing may ruin the hollow fiber membrane. If in freezing conditions we recommend you keep the filter in your pocket or near your body to prevent freezing. Capacity: 750 ml Weight: 116 g Dimensions: 228 mm x 107 mm / 11 in x 3.1 in Material: TPU, PP, Silicone, POM, TPE, ABS, Hollow Fiber, Polyester, EVA, Nylon