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SteriPEN Classic Water Purifier with Prefilter

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  • Ultraviolet (UV-C) light rays safely sterilize clear water by destroying 99.99% of viruses, bacteria and protozoa, including Giardia and Cryptosporidium
  • SteriPEN protects you from risks that cause botulism, cholera, dysentery and typhoid, just to name a few
  • But if clear water is not available, no worries—the SteriPEN prefilter clears particulates and debris from water
  • Prefilter fits Nalgene® and other water bottles with 63mm wide-mouth openings; pour source water through filter, and clean water enters bottle
  • Then use the SteriPEN purifier to treat the water; just press a button and gently agitate the water with a quick stir
  • Purifies 16 fl. oz. of water (cold or warm) in less than a minute or 32 fl. oz. in a minute and a half
  • Small size fits most containers—use it in cups, mugs, water bottles and canteens
  • SteriPEN turns itself off once ultraviolet treatment is complete; can be used up to 8,000 times!
  • Watertight seals keep water away from the electronics; rubberized inset grips for secure handling in wet conditions
  • Low-power indicator lets you know when batteries need replacing; twist-off cap for easy battery access
  • Long used by municipal water districts and bottling companies, low-level UV-C light treats water safely, and unit's light will not damage eyes or skin
  • Purify 200 16 fl. oz. glasses of water with 4 lithium AA batteries (batteries sold separately)
  • SteriPEN recommends the use of name-brand lithium AA batteries with a capacity of 800 milliamp hours (mAh) or greater, such as Duracell, Energizer and Panasonic
  • SteriPEN does not recommend the use of alkaline batteries, as they provide very few SteriPEN treatments
  • Nickel-metal hydride (NiMH) rechargeable batteries are approved for use; be sure to fully charge batteries before use
  • Average weight is 8 oz. with alkaline batteries and 6.4 oz. with lithium batteries; weight empty is 3.7 oz.
  • Only use SteriPEN independent of prefilter when clear water is available, as cloudy, sediment-laden water hinders effectiveness
  • Prefilter screen has a square aperture equal to 17 square microns
  • Includes SteriPEN Classic water purifier, prefilter, carrying case and instruction manuals

Since late 2008, all SteriPEN water sensors feature twice the electrode voltage of older models. The increased electrical current flow allows proper function in water with low conductivity such as snowmelt and even mineral-free distilled water.


Item 761906

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SteriPEN Classic Water Purifier with Prefilter Specs
Best use
Ultraviolet light
Protozoa, bacteria and viruses
Not applicable
Not applicable
32 oz. per 90 seconds
Not applicable
7.6 x 1.5 x 1.5 inches
6.4 ounces
Filter type
Filter medium
Pump force
Pump strokes per liter
Housing material
Field cleanable

SteriPEN Classic Water Purifier with Prefilter

Loading Ratings & Reviews...

Rated 3.5806/5 based on 93 reviews
Rated 1out of5
by fromPiece of junk Just returned from Thailand and Laos. Used this product twice, then the 4 batteries died, drained. No indication, and UV light wouldn't go on. Very expensive, and very dissappointed. Had to buy bottled water during whole 3-week trip.
Date published: 2007-11-09
Rated 1out of5
by fromCompletely fails in the tropics The Steripen DOES NOT work in the tropics! We have had several pens on our project fail completely within 2 days. I notice that a Thailand traveler reported a similar problem. Back home in the US, the pens "fix" themselves... goading the unsuspecting user into bringing them back a second time, where they immediately fail. The green light flashes, red light flashes once or repeatedly, and then that's it. Scrubbing the pins and battery contact points helps once or twice, but no further. This may have something to do with corrosion in the humid climate, or moisture accumulation within the bulb. The batteries in other tech equipment and GPS's work without fail. Cute little gadget, but totally useless when you really need it.
Date published: 2008-03-17
Rated 1out of5
by fromUnreliable Tested many times at home and it worked fine. Worked first time in the backcountry then nada. Changed batteries - nada. Clciked the button rlentlessley - you guessed it - nada. Glad I was with others who had traditional filters. If you must use one of these and hike alone - take iodine tablets.
Date published: 2008-09-27
Rated 1out of5
by fromDefective out of the box I was so disappointed when I opened this product after purchase to test it. The unit never worked...not once. The green light would come on, the red light would come on, but the UV light never worked. I tried everything...drying the sensors, a second set of new batteries, adding a pinch of salt to the water, all to no avail. I realized after all the troubleshooting info and other reviews I have read outligning other's problems with the Steri-Pen, I realize that I'd rather stick to a non-electric puifier. Even if it worked, the potential for failure is too great to worry about while out in the back country.
Date published: 2008-10-03
Rated 1out of5
by fromFails in tropical/humid enviroments Used one extensively traveling in Nepal and China worked great. Traveled in Jamaica and the Yucatan of Mexico with a total of four pens and all four failed to work. Had to use backup system (iodine aguamira) etc. The noted difference was the humid environment. When it works they are great but based on personal experience and other travler response reliability is a consideration especially if traveling overseas for extended period of time.
Date published: 2009-04-13
Rated 1out of5
by fromVery unreliable I have had two of these now and both have broken. [...] The new one worked once really well, cleaned about 20L and it was great, but the next time I used it, it started doing an assortment of different things, which is very frustrating. From turning off after sterilizing for 10 seconds, low battery warnings with new batteries, not working at all, getting water in the light, all kinds of ridiculous things that you do not want to deal with in the back country. I really wish it was reliable because it is a great idea, but it's not worth carrying around if you don't know when it will work, simple as that. I would stick with the tried and true filter or tablets (which a backpacker should always carry regardless).
Date published: 2009-08-20
Rated 1out of5
by fromDidn't work I based this review on not getting to use this. I set it up at home and tested it out just fine. So I packed it for a 3 day trip to the Pecos Wilderness and after filing the second bottleful of water it stopped working. Some kind of fault, I'm assuming battery - but I started out with new batteries. Also, I got wet while filling the cap with water, which was very COLD at the time. Ended up using my companions pump. HAVE EXTRA BATTERIES AND A BACKUP SYSTEM!
Date published: 2010-01-03
Rated 1out of5
by fromToo much chance for cross-contamination My Sweetwater needed a new filter, so I decided to give this UV pen a try instead on my last weekend backpacking excursion in the mountains. What a mistake that was! First off, you really need to use two containers: one for collecting the water from the stream, then another to pour the water in through the pre-filter. That is the only way you have even a fighting chance of avoiding contact with untreated water on your treated water container. The instructions say you can use the "immersion" method of filling through the prefilter, but that looks like a great way to contaminate the outside of the bottle, your hands, etc. It's way too easy to get untreated water on the threads and rim of the bottle you are treating, even using the "pour through" prefilter method, meaning your UV-treated water will just get re-contaminated as you pour it out (or worse, drink from the rim of the bottle). The instructions say you should "wipe off droplets" from the bottle threads. Like that is going to remove germs? Second, even though the manufacturer claims the new versions work in snow melt source water, I'm not convinced. I got sick as a dog despite following the instructions to the letter and using a separate collection bottle to gather the water and pour it through the prefilter into my "clean" bottle. I am returning this gadget and going back to my tried-and-true Sweetwater filter pump where I can easily keep untreated water from ever touching my water bottles. I've never gotten sick after 5+ years using my pump with some pretty nasty water sources. I see there are plenty of positive reviews of this UV pen, but I'm guessing those folks either don't use them much or have been very lucky in that their water souce was fairly bug-free and chemical free to begin with. Which brings me to my last complaint with this thing: this UV pen and prefilter will NOT remove trace organic chemical contaminants like an active charcoal filter will. I'm giving this UV device a big thumbs down for backwoods travel.
Date published: 2010-03-29

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