Visit our Showroom or Book an Appointment

More Info


Hydrapak 42mm Filter Cap

The Hydrapak 42mm Filter Cap is a water filtration cartridge that seamlessly fits onto any Hydrapak (or any other brand) water vessel or bottle with a 42mm cap allowing you to filter and drink from any source whilst out in the wild.

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 or Flux. Both deliver fast and easy water treatment around camp or on the go. FULL FILTER SPEC SHEET.


  • LIGHT & COMPACT: At only 57 grams, our filter is one of the lightest filter options available. Its small size takes up no extra space when stored or threaded directly onto a Seeker or Flux.
  • DUST COVER & HIGH-FLOW NOZZLE: Keeps dust off your drink nozzle. Quickly opens and closes the drink nozzle with one hand without any direct contact with dirty hands.
  • 42MM THREAD COMPATIBLE: Easily thread the filter onto some of the most popular backpacking water storage bags and flexible bottles including the HydraPak Seeker 2L, 3L, 4L, and 6L and 1L and the Flux 750ML, 1L, and 1.5L
  • FAST & SAFE FILTRATION: Removes 99.99% of E Coli & Parasitic cysts. Filters approximately 1,500 liters of fresh water at a rate of >1 L per minute.
  • SAFE: Filter removes Escherichia coli bacteria, Cryptosporidium parvum cysts, and Giardia Lamblia (99.9%) from approximately 1,500 liters of water.
  • SAFE & RELIABLE: 100% BPA and PVC Free


  • Weight: 57g 
  • Dimensions: 42mm Cap Compatible
  • Material: PP/POM, EPDM, Silicone, Hollow Fiber

    Personal Shopping - By Appointment

    Would you like to try on some climbing shoes, running shoes or mountain boots for size before you make your purchase? If so, then why not book an appointment with us today! We can offer you a bespoke one-on-one shopping experience with one of our experienced staff members.