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      SteriPEN Adventurer Opti Water Purifier

      The smallest, lightest SteriPEN, the SteriPEN Adventurer Opti Water Purifier uses a revolutionary optical eye to sense and purify the water in even the coldest of conditions.
      • $89.95

      Item # 799003

      REI Members get back an estimated $9.00 on this item as part of their annual member refund.
      Product size and color

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      • details
      • specs
      • reviews
      • q & a
      • New optical sensor doubles as a convenient LED flashlight
      • Flashlight mode is activated by pressing and holding the single button down for 3 seconds
      • Clear lamp cover focuses the LED light
      • Retail package includes 2 non-rechargeable (disposable) CR123 batteries and a neoprene case with belt loop
      • Device works with containers with minimum 1.75 in. diameter opening (i.e. Nalgene wide-mouth bottles)
      • Battery life: disposable—100 treatments (16 oz../0.5 liter); rechargeable—40-50 treatments (16 oz../0.5 liter)
      • UV lamp life: 8,000 treatments

      SteriPEN water purifiers meet U.S. Environmental Protection Agency standards for microbiological water purifiers and have been independently tested by the Oregon Health Sciences University and the universities of Arizona and Maine. For complete test results visit


      SteriPEN Adventurer Opti Water Purifier

      Specification Description
      Best use Backpacking
      Filter type Ultraviolet
      Filter medium Ultraviolet light
      Removes/Destroys Protozoa, bacteria and viruses
      Pump force Not applicable
      Pump strokes per liter Not applicable
      Output 32 fl. oz. per 90 seconds
      Housing material Not applicable
      Field cleanable Yes
      Dimensions 6.1 x 1.5 x 1 inches
      Weight (With batteries) 3.6 ounces

      SteriPEN Adventurer Opti Water Purifier

      Loading Ratings & Reviews...

      Rated 1out of5
      by from[...] JUNK, JUNK, junk, If you want to waste your time this is the item for you. Shoddily made imported garbage should NOT make it onto R.E.I.'s shelves. But IT DOES. This is so poorly made it didn't even survive opening the battery compartment. I wouldn't give this to an enemy much less a friend. When I tried to register the item online the prompt required me to open the battery compartment to check the serial number, which wasn't there. Upon reassembly I attempted to replace the screw top cap. The cap wouldn't close or allow the battery compartment to be opened at all. Total shoddy junk. It seemed like the assembly from a 2$ l.e.d. flashlight I own, NOT a near 100$ water purifier. If it cannot survive the battery compartment being opened ,what makes anyone think this toy will save you from impure water. Items that are lifesaving tools should NOT be made poorly. Great IDEA. EXTREMELY poor design. If I could have given this item 0 stars I would have. Don't waste your time. Get a "real" water "filter". Not a shoddy toy.
      Date published: 2011-06-26
      Rated 1out of5
      by fromFailed second time out The Steripen failed when in the backcountry. Red light flashed after a few seconds indicating low batteries, strange having low batteries given the unit had only been used to filter about 4L, changed batteries only to have the same issue red light flashes within seconds of activation. [...]
      Date published: 2011-07-28
      Rated 1out of5
      by fromUndependable I had the occasion to make my first use of a new SteriPEN on a recent backpack trip with others. The device worked occasionally, but it failed far more often despite our following the directions to the letter. Fortunately, one in our party brought along a dependable water filter. We gave up on the SteriPEN and relied on proven, though a bit weightier, technology. By way of aside, one in our party suggested that holding a UV light close to the body could not be good. I don't know if that is the case. If it is, that would be yet another reason to forego this costly novelty.
      Date published: 2011-08-14
      Rated 1out of5
      by fromDon't Waste Money or Take Back-Up I have been backpacking the Sierras for the past 20+ years. Based on a friend's recommendation and the great reviews on this website, I purchased the SteriPen Adventurer Opi and left my MSR Sweetwater purifier behind for my four day back packing trip in the Sierras. The manufacturer promises 50 liters of use, however, I only received 20 at best. Due to the battery failure after purifying just 20 liters of water I had to boil water for the second half of my trip. Besides the awful taste, boiling water also greatly hinders your ability to be mobile. We also had to forego cooking our food so that we had sufficient fuel to purify our water. I was EXTREMELY disappointed with this product. It negatively impacted my one and only vacation this year.
      Date published: 2011-08-24
      Rated 1out of5
      by fromUnreliable sterilization We bought this for a 2 week backpack at Mount Rainier. It worked well for the first 3 days, then stopped working. We changed batteries and it worked again for a few days, and stopped working. Clearly, it was not just the battery life that was the problem. In the end, we relied on the chlorine dioxide we brought as a backup. We returned this product as I would rather just have one reliable method. In addition, it is hard to see the light, especially depending on the color of the water bottle.
      Date published: 2011-08-24
      Rated 1out of5
      by fromJunk don't trust this! Good thing for us we brought a back up system! This thing worked fine for about 5 gallons of water then went berzerk. Changed battery still went nutz--don't trust this item it will stop working when you least expect it.
      Date published: 2011-08-30
      Rated 2out of5
      by fromActivation switch is terrible This product would be great but it is extremely difficult to get the activation button to work. I took mine back to REI and had it replaced twice but the same problem occured. I contacted Steripen and they say it should not be so difficult to turn on but both of the ones I got were nearly impossible. It literally took squeezing with two hands to get it to turn on. In a survival situation this would not be a good product to have expecially if you are injured, weak or sick. I cannot recommend this product.
      Date published: 2010-09-08
      Rated 2out of5
      by fromActivation button very stiff I've used the prior Adventure model for about 20 days of backcountry use. Its worked very well for me. I upgraded to the new Opti model based the improvements to battery drain while stored and the optical sensor. The activation button was so hard to press, I couldnt tell if I successfully clicked it once or twice, which makes a difference since this is how you set a half or full liter dosage. With the prior model, the click feel of the button was easy to notice. Had to return this, hopefully this will be addressed, but based on other reviews here others seem to have had the same experience. I'd give this five stars and would have kept it if not for the button issue.
      Date published: 2010-12-09

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