HydraPak Ultraflask 42mm Filter Cap bis_hidden Generous 475ml capacity for more

Generous 475ml capacity for more of your favorite hot or cold drink

80 Denier GORE-TEX Pro Most Breathable Technology across the shoulders

Minimal seams with seamless design in the pack body

Blanket or bag

Easily thread the filter onto some of the most popular backpacking bottles and flasks including the HydraPak Stow 500ML and 1L and the 1L Smart Water Bottle

HydraPak Ultraflask 42mm Filter Cap bis_hidden Generous 475ml capacity for moreFiltration For Runners Overview Run fast, filter faster. The UltraFlask+ Filter Cap threads seamless onto all of HydraPaks 42mm running flasks and handhelds for a lightweight, straightforward filtration solution. Featuring a traditional bite valve and cap design, runners can drink freshly filtered water directly through the high flow Blaster valve. *Effectively removes common waterborne bacteria, such as E. coli (99. 999%) and parasitic cysts (99.