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MSR Guardian Purifier


MSR Guardian Purifier


Brand: MSR
  EAN 0040818023709
Weight: 490 g         3 reviews
The MSR Guardian Purifier is the world’s most advanced backcountry purifier. Nothing is safer and easier to use for purifying the most demanding backcountry water sources.

Originally this product was designed for the millitary, but now it is available to global trekkers and backcountry users along with those stocking emergency kits. It offers added viral protection you need when traveling in developing nations and in popular wilderness areas.

This purifier meets NSF protocol P248, testing standard used by U.S. military, for removal of viruses, bacteria, protozoa, and sediment from “worst-case” water conditions and it is engineered to withstand heavy use, freezing, drops, and harsh environments.

The MSR Guardian Purifier is field maintainable and has a self flush system which cleans the filter itself with 10% of the filtered water, which is revolutionary in Ray's opinion. It pumps a rapid 2.5 litres per minute, offering added viral protection without the need for chemicals, bulbs or batteries. Ray particularly recommends this purifier for groups of people travelling together or at base camp due to the high volumes of water that can be purified so quickly.

  • Filter media is made from an advanced medical grade hollow fiber material
  • Filter pore size is 0.02 microns
  • Flow rate 2.5 litres per minute
  • Cartridge life 10,000 + liters
  • Includes a cartridge replacement indicator
  • Extremely durable, engineered to withstand heavy use, freezing temperatuers and harsh environments
  • Drop tested (lab testing 6ft to concrete)
  • Water bottle adapter included
  • Self-cleaning filter
  • Includes travel bag
  • Effective against bacteria, Protozoa and viruses
  • Removes particulates such as sediment, silt and dirt
  • Size: 21 cm x 12 cm
  • 3-year Limited Warranty
  • Made in the USA


  Next day delivery within the United Kingdom
  UK Orders placed before 2PM GMT will be dispatched the same working day
  Overseas delivery times will vary depending on the destination

Please note that our offices are closed at weekends, so any orders placed after 2PM GMT on a Friday will not be dispatched until the following Monday.

Please note that in some instances, orders for heavy items may take an extra day to arrive.

  Overseas deliveries
For overseas deliveries, please refer to the following estimated delivery times:

  • Europe: 3 - 5 working days
  • Rest of the world: 5 - 7 working days


A full refund or exchange will be given provided that the items have not been worn or used, and are returned to us within 30 days of purchase, together with all relative labels and packaging. You are responsible for the cost of returning items.

Please ensure that you include a copy of your invoice, along with an explanation of why you have returned your goods. If you wish to return your goods for any reason, please do so to the following address:

Woodlore Limited
PO Box 3
East Sussex
TN19 7ZE
United Kingdom

Product Video

Product Reviews

MSR Guardian Purifier is rated 5/5 based on 3 customer reviews.

All of our product reviews are from customers with verified purchases.

Overall Rating:


  1 of 3

  Fast delivery, and competitive pricing, but I can’t review the item yet. Will being off to the mountains next week, and will filtering some streams there.  

  Greg S
3rd April, 2022

Rated: 5/5

  2 of 3

  Now this is something I wished I had many years ago. Well made, not too heavy and works extremely well. I have had no issues with it. Expensive yes, but it's once again a piece of mind thing when in a region of unknown water quality.  

  Sean B Kelly
26th June, 2019

Rated: 5/5

  3 of 3

  I brought this water filter as my previous water filter would not be up to the standard needed on my walking trip. I multi-day walked for 6-7 days and needed something I could trust to give me the cleanest fresh water possible in boggy moorland, wilderness, moving through very heavily used sheep country. I could not guarantee the water quality and took water from some very dodgy water sources bog/marsh, ponds, lakes, quarries, streams and ditches. I would not have taken water in these places with my other well known good water filter system. I can say I had no stomach issues at all, I felt fine the entire time of walking and drinking from natural water sources. The water tasted fine with no after taste, all the water was clear with no foreign matter. It is fast and I got about 2 litres of water in a minute, a lot faster than my other water system, 1 litre in about 5 minutes Other Walkers said 'you can't drink from that!', I took water and was fine, I never had to worry about carrying lots of water or finding water, which was a big relief to me. For me, it has made life easier and safer, I can trust the MSR Guardian to keep me safe from poor water sources while out in the wilderness long distance walking and camping. It is expensive, but to have clean drinking water and not be ill on the trail or long term illness from the water you drink, to me its cheap, my health comes first. It is now my go to water system and one of my most valuable items of kit. I would recommend watching the MSR videos on the filter, it is very interesting, it is well made and sturdy and comes in a nice bag. Woodlore sent the purifier very quickly and got it to me very fast, which was just as well, as it was a last minute purchase for the trip. Thank you for your very quick service and reply email, I am very happy with my MSR Guardian water Purifier and will use it on all my trips for years to come.  

  Caroline Light
2nd May, 2019

Rated: 5/5

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