The UltraFlask  Filter Cap threads seamless onto all of HydraPak’s 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.

FILTER FACT SHEET | FILTER USER MANUAL

*Effectively removes common waterborne bacteria, such as E.coli (99.999%) and parasitic cysts (99.9999%) per HSF 42.