I was a bit disapointed with this product. The first time I used it it was fantastic. Filtered a large amount of water in no time at at. However the performance drops off extremely quickly and by day 5 of a 16 day trip it wouldn't even filter a bag full in a 24 hour period despite numerous cleans of the filter. i would not recomend this product. It certainly doesn't do what Katadyn reports (apart from the first 5 times you use it.