I played with the purifier this evening. Pretty neat. I filled the sink with soapy dishwater, filtered it, tasted fine. I will try a muddy puddle next time it rains. Very easy to use and light weight. Katadyn bought the rights to it from PUR a few years ago. PUR sold it for 79.95 by what the box mine came in says. Now it sells for couple hundred bucks, it even uses the same filter? Gotta pay for that name...