Hydrapak Filter Cap Water Filtration Accessory 42mm

Reviews

• Vincent L.

  Rated 5 out of 5

  Filter Cap for running soft flasks that LOCKS!

  10/28/26

  Love this thing. Ever since I started using the hydrapak locking caps on all my softflasks, I couldn't believe hydrapak didn't make a locking filter cap as well. while this isn't exactly the same, it has that same function. Works great with soft flasks. I even prefer this when fast packing as you can filter water without having to squeeze or remove the nozzle, which makes it a much easier operation. highly recommend, especially to carry water in your pack without risk of leakage.

• Nathalie G.

  Rated 5 out of 5

  Excellent

  06/22/26

  Produit très pratique et efficace.

• Bill R.

  Rated 5 out of 5

  HydraPak 42mm filter cap

  06/15/26

  These caps are game changers! Using these with seekers and flux flasks trumps the old ways of filtering water with agonizingly slow gravity systems and laborious pumps with ceramic filters that need cleaning every 3-4 liters. Highly recommended!

• Henny H.

  Rated 5 out of 5

  Amazing little filter

  12/18/25

  Filters works flawlessly, so easy and convenient. Second filter purchase and will continue to use it

• Laurent T.

  Rated 5 out of 5

  Fits perfectly on 42mm threads

  12/17/25

  Perfect for my soft water bottles. More compact than the screw on filter that sits on top of the bottle. If you use a running vest style pack, having the filter inside the bottle means you’re not at ris of getting poked in the eyes by a filter that screws on top. Fast flow so far in clean water. Can’t wait to test it in silty water in the spring.

• Mathieu

  Rated 5 out of 5

  Replacement filter

  09/26/25

  Replacement filter for a great flexible and compact filtration system. The filter provides clean water with a good flow rate. Great for single or multi-day hikes.

• Kimberley R.

  Rated 5 out of 5

  Nice compact filter

  09/09/25

  This is a nice light filter that I added to my hydrapak water bottle. Fits the opening of the bottle perfectly. Doesn’t add any bulk and great for day hikes to quickly drink water from a creek if needed.

• Antonio S.

  Rated 5 out of 5

  Great replacement filter

  08/15/25

  I was hesitant to buy this because of the different flow valve, but it works great. I used it while trail running to refill my soft flasks. It’s easy to use and the flow rate is better than my Salomon Xa filter and the Katadyn filter.

• Kris V.

  Rated 5 out of 5

  Hydrapak water filter

  08/15/25

  This is exactly what I was looking for. Allows me to quickly filter water while trail running so I don’t have to carry extra water. Very happy with my purchase!

• Stacey C.

  Rated 5 out of 5

  Recommended by a friend

  08/14/25

  I'm looking forward to using this filter on my next backcountry adventure. I like that it's compact, easy-to-use and compatible with the soft flasks that came with my running pack.