Several years ago I purchased this water purifier largely due to the size of the device and it's endorsement by Ray Mears.
As the first water purification device that I had bought it was a reasonable price and seemed quite good in terms of performance, however as I go walking with larger groups I have found that I am using other water purification products that purify far greater quantities of water with less physical effort.
These days this device has found it's way into my emergency kit - it's very light, can purify a reasonable amount of water prior to filter needing to be replaced and also is effective against viruses.
This is definately a filter suitable only for an individual rather then a group and perhaps better suited as a introductory device to someone new to the equipment.
(Written by: sthwaites)