I bought this thinking it would be perfect. I read the reviews and disregarded the negatives I read thinking the reviewers must be imprperly using the steripen or if the negatives were true surely the maufacturer would have fixed any issues with this newest model. I was wrong. When the unit worked it was effortless and magical however, it mostly didn't work which made me forget about the magic I experienced when it did work. I took this out for a 6 day trip and it worked all of three quarts on the first day and that was it. I followed all instructions and even kept the pen in my pocket the whole time to keep it warm. I tried it at home after returning and it did not work on my tap water either. I added salt per the previous reviewers suggestion and all it did was create salty untreated water. I love the concept and hope they make it reliable for use in the field in the future but this is not. Water is to important to leave to chance.

Would you buy a car designed by ferrari, and built by ford. I hope not. This is a great product idea which I really want to love. However, it looks and feels like a toy from the dollar store. Poor h20 proof battery seal, (utilizes a bogus O ring) which falls off way too easily. Batteries don't last. It works only when god wants it to. I took it on a two week outdoor survival course, and it quit working after 10-14 nalgenes. I replaced it, thinking it was just a lemon. Then backpacking in So Ut with it's replacement, it quit working one day into the trip, with new batteries. For an item that will either keep your body healthy and sustained or in peril, it has been built like a chinese water pistol. The customer service was terrible the 1st go around. Now on the 2nd they seem to acknowledge a flaw and have been a bit more helpful, which is irreleavent to the fact that it is hokey pokey piece of gear. My buddy has the Adventurer model, which seems to be a little better built and had no problems over two months of periodic use on the original batteries. If you want to give one a try, don't get the journey, the frowny or smiley face is cute and all, but a green and red light on the Adventurer will tell your Pavlonian mind the same thing. Green=good red=bad

Hi, I had the same issue with the unit not completing a cycle and receiving the dreaded frown face. The problem is the conductivity of the water was too low for the probes to recognize they are indeed in water. Perfectly distilled water does not conduct electricity, small (microscopic)dissolved particles within the water do. In essence the water was almost too clean for the unit to work, that being said I still wouldn't risk not treating the water. I just added a very small amount of juice crystals to the water in question and the unit worked without a hitch. I also tried collecting water where wave action on the lake at the shoreline would stir enough particles in the water to make the unit work, this also worked well. Please note this is only for rare instances where water is so clean that the unit won't otherwise work. For the most part you should still try to find the clearest water possible. We must both hike in the best places to have such great water. Hope this helps.

Saw a SteriPEN Journey model in action recently. Pretty cool. Does the same thing as the other models but adds alot more user friendly information on the small LCD screen. It counts down the time you have to wait until the water is purified and gives you information on battery life, dosage, etc. A smiley face appears if your water is ready to drink...a frowny face if not. Takes some of the guesswork out. Seems like a worthwhile upgrade to the other models for the extra information given.

Reliability has been questionable. I have used this cool gadget on two weekend backcountry trips. When it works properly it is an amazing product, however sometimes, and more often than not on my last trip, the unit would not engage properly. The light would flash on and then "frown" from LCD would appear, and yes the batteries are new a yes the water was making complete contact with the sensors. I cannnot explain why this happened, very frustrating, It may be an air bubble issue over the contacts when inserted into the Nalgene bottle. Just be mindful of this situation. Overall a cool gadget but if I was alone in the woods with only this as my lone water filter for over a couple of days I might be concerned.