Filter water on the go. The new 42MM Filter Cap threads seamlessly onto all sizes of HydraPak’s 42MM threaded Seeker water storage bags and Flux flexible bottles morphing them into filtration solutions. The end result being lightweight filtration kits that can either be used to squeeze filtered potable water into other camp bottles and containers or to drink freshly filtered water from a Seeker, Flux, UltraFlask or SkyFlask. Both deliver fast and easy water treatment around camp or on the go

Greg's Take:

The Hydrapak water filter cap is a no brainer when out on the trails for a full day. It pairs with most flasks on the market for a worry free resupply of fresh mountain water. Just shake or swish water around in your flask to clean the filter and you're good to go!