HydraPak 42mm Filter Cap - Water Filtration Accessory - Fast Flow - Perfect for Hiking, Endurance Sports, Camping, Travel, and Emergency Preparedness

I’ve used the HydraPak 42mm Filter Cap on multiple trail runs and backpacking trips, and it’s quickly become one of my favorite pieces of gear. The fast flow rate makes it super convenient...you don’t have to wait long to fill up or squeeze hard to get clean water. On long runs, I’ve been able to scoop water from streams and keep moving without slowing down too much. The design is simple and lightweight, and it pairs perfectly with my HydraPak soft flasks and reservoirs. I really appreciate how compact it is, easy to stash in a pocket or side pouch without adding bulk. Even after repeated use, it still works smoothly and hasn’t clogged up. Overall, this filter is reliable, quick, and perfect for anyone who wants a hassle-free hydration solution on the move. It’s a must-have for trail runners, hikers, and backpackers looking for a lightweight water filter that just works.

Perfect replacement fit - best filter system on the market for size, quality, and pack weight. I did not follow proper long term storage procedures and required a replacement cartridge for my AT section hike. In hindsight, I should replace the filter annually.

Easily my favorite backpacking water filtration system I’ve used to date. Flow is superior to sawyer and platypus. In fact it’s so fast that I have doubts it’s actually filtering anything, although Ive never been sick afterwards. Will be purchasing more.

Hopefully HydraPak is reading this. Love the idea and this filter flows water well. I've used it on 3 camping trips so far, 3-4 days each, and on the last trip I noticed the cap is cracking. The end that locks the cap closed is cracked and a small bit of material is missing that wasn't when new. The center top of the cap has several cracks in it. The filter is good but would be much much better if it lasted longer. That is the only reason for a lower rating here. A cracked cap renders the filter contaminated and worthless for its intended purpose and, thus, unusable. Update: I submitted a claim for service to HydraPak and they came through with a warranty replacement of the filter. Received the new replacement filter cartridge earlier this week. I will see how it performs during the next 2 camping trips in September but I do really like this system so far.

Have used these the last few years in the Colorado high country for filtering water. The hydrapak bags seem to be better than Sawyer bags. Fast flow. Have not had issues with clogging as long as you use decent water to start and are careful up front to avoid sediment.

These work great combined with the 2 liter bottle they sell. We used these on a recent trip to South America where water from the tap was not drinkable. We poured tap water to the 2 liter bottle then filtered it into other reusable bottles we brought with us. We also have a Travel Berkey we bring if the water is really sketchy (with pre-treatment using plain bleach as needed to kill virus and amoebas). The flow rate on this filter is great and you can’t get a lighter system to travel with.

I use this with the 4L seeker for backpacking and I love it. Just fill it up when ever I am near water and fill up my nalgene or boil pot when ever I need water. This replaces my 3L water sleeve and removes the need to pump/filter water to refill my reservoirs. Not I just filter water when I need it. It filters pretty fast, but I have not tested yet with murkier water sources yet. Had good water sources this year in the back country.

Lifesaver for filtering water on long runs. Be sure to flush it first or it will have a bad taste

Great filter. Used for 20+ days in the backcountry this year. Filtering mostly clean creek water most of the time. Flow rate is excellent. Would recommend.

S'adapte parfaitement à ma flasque Salomon 42mm nickel

Brilliant filter, recommend buying with the seeker for best result

This filter has made the hydrapak 2L flexible bottle even more versatile on our multi day hikes.

Es un filtro muy bueno y aunque no tiene tanto caudal como el katadyn befree cumple igual de bien. Además me gusta más este por su tapón (motivo por el que prefiero este al katadyn). Nunca se te va a abrir por accidente, no entra suciedad y se ve muy resistente. Yo he estado bebiendo de un charco en una pista forestal durante un día con esto y no he tenido ningún problema Combinado con la botella hydrapak flux tienes un equipo de filtración perfecto. No tienes que mojarte la mano pues tiene un asa para coger agua de donde sea. Como es medianamente rígida se aguanta de pie y es super duradero. Lo único malo es el sabor a plástico que tienen todas las cosas de plástico flexible como camelbaks y demas... Recomiendo darle unos cuantos lavados con bicarbonato, se reduce mucho el sabor aunque nunca desaparece. 10/10