The MSR Guardian water purifier goes with me on every wild camping trip (for example, my 2-month walk from Land’s End to John O’Groats and the Cape Wrath Trail). It’s not exactly lightweight – in fact it’s one of the heaviest water filters around. However, I think it’s worth the extra weight because it is so quick and easy to filter water with this.
It is one of the safest filters you can buy, and was originally designed for military use. You can use this to filter even filthy water if you have to. This means I can compensate for its heavier weight by not carrying so much water in the first place. I know I will be able to get clean water from somewhere when I am carrying the MSR Guardian water purifier.
The other thing I really like about this water filter is the fact that it is maintenance-free. It even cleans itself. The filter can be replaced, but it is designed to filter a lot of water before you need to replace it. This makes it better value for money than it might appear at first, especially if you are going to be using it a lot.
It is an extremely tough, durable and useful product. Highly recommended.