FAST & SAFE FILTRATION: 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.* LIGHT AND COMPACT: Minimal design and lightweight materials make this filter the ideal choice for runners. It takes up no extra space when stored or threaded directly onto a flask. HIGH-FLOW: Easy to drink bite valve auto-seals after each sip, eliminating annoying drips. COMPATIBLE: Perfect for trail running or backcountry water filtration. Works with all 42mm opening HydraPak products including running flasks, Seekers and Flux bottles. INCLUDED BACKFLUSH ADAPTER: Plugs into filter valve and threads onto a HydraPak Stow or bottle of clean water for backflushing the filter to restore its flow rate.