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SteriPEN Adventurer Opti Water Purifier

    SteriPEN Adventurer Opti Water Purifier

    The SteriPEN Adventurer Opti water purifier is equipped with a new optical water sensor for reliable performance so you can enjoy clean, purified water on the go. See details

    • $89.95

    Item # 799003

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    The SteriPEN Adventurer Opti water purifier is equipped with a new optical water sensor for reliable performance so you can enjoy clean, purified water on the go.

    Product size and color

    The SteriPEN Adventurer Opti water purifier is equipped with a new optical water sensor for reliable performance so you can enjoy clean, purified water on the go.

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    The SteriPEN Adventurer Opti water purifier is equipped with a new optical water sensor for reliable performance so you can enjoy clean, purified water on the go.

    • From 2011 Backpacker Editors’ Choice awards: “Our testers have tried every water-treatment method available, and for most trips and conditions, this one beats them all”
    • SteriPEN Opti features an optical water sensor that detects whether or not the device is in water and only allows the UV lamp to activate when the SteriPEN is immersed
    • After pressing the button to activate the SteriPEN, immerse the lamp and optical sensor; the UV lamp will then activate and emit UV light and visible blue light
    • Optical sensor doubles as a backup LED flashlight that can be handy when walking to the stream to get water; operate flashlight with SteriPEN cap in place to protect the lamp
    • Adventurer Opti requires no pumping, chemicals, test strips, extended time-keeping or filters; leaves no aftertaste, will not clog and does not require lubrication
    • Innovative SteriPEN system uses UV light rays instead of chemicals to purify water for drinking
    • Ultraviolet (UV-C) light rays safely sterilize clear water by destroying 99.99% of protozoa (including Giardia and Cryptosporidia ), bacteria and even viruses
    • 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 when used properly
    • SteriPEN protects you from risks that cause botulism, cholera, dysentery and typhoid, just to name a few
    • SteriPEN Adventurer Opti is simple to use: 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; carries easily in a shirt pocket
    • SteriPEN Adventurer Opti turns itself off once ultraviolet treatment is complete; light source can be used up to 8,000 times!
    • Watertight seals keep water away from the electronics; rubberized coating ensures secure handling in wet conditions
    • Low-power indicator lets you know when batteries need replacing; screw-off cap permits easy battery access
    • Use only on clear water, as cloudy, sediment-laden water hinders effectiveness; FitsAll prefilter (sold separately) clears particulates and debris from water
    • SteriPEN Adventurer Opti includes 2 nonrechargeable lithium CR123 batteries; SteriPEN does not recommend the use of alkaline batteries, as they provide very few treatments
    • SteriPEN recommends the use of name-brand CR123 lithium batteries with a capacity of 800 milliamp hours (mAh) or greater, such as Duracell, Energizer and Panasonic
    • SteriPEN Adventurer Opti water purifier includes a neoprene carrying case with belt loop

    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

    Items with a lithium battery can only be sent via Standard ground shipping, and can't be shipped to P.O. Boxes, Alaska, Hawaii, U.S. Territory, APO/FPO, or International addresses.


    Item 799003

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    SteriPEN Adventurer Opti Water Purifier Specs
    Best use
    Ultraviolet light
    Protozoa, bacteria and viruses
    Not applicable
    Not applicable
    32 fl. oz. per 90 seconds
    Not applicable
    6.1 x 1.5 x 1 inches
    (With batteries) 3.6 ounces
    Filter type
    Filter medium
    Pump force
    Pump strokes per liter
    Housing material
    Field cleanable

    SteriPEN Adventurer Opti Water Purifier

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    SteriPEN Adventurer Opti Water Purifieris rated3.7667out of5by30.
    Rated1out of5byfromCold or Winter conditions = UselessI do not want to criticize this company or its products, only relay a personal experience in case it helps. I brought this on a multi day trip on the AT in colder conditions last year to lighten up my pack load, and try something "new" for purifying my water supply. It was a complete failure. This does NOT work well in colder conditions (10-20 degree ranges.) I kept it wrapped in heavy socks in top of my pack for easy access and protection, but 7 miles into our hike on the first day I tried to use it and it died immediately after I turned it on. Brand new batteries. I had back up's, put them in, and the same thing happened. So, this is not a a good application to bring out into colder conditions. I would imagine its awesome for international travel (would buy it for that) but for anything outdoors where you need it deeper in the woods, I would leave it at home. Buyer beware :)
    Date published: 2014-01-29
    Rated1out of5byfromNot worth the HassleI had planned on using this filter system while thru-hiking the AT but it failed me twice with-in the first month of being on trail. There is no screen showing the battery life which resulted in the batteries to die on me twice while in the middle of the woods and had to drink dirty until I could make it into the next town. The batteries are expensive at about 10-15 a battery with it taking 2 batteries at a time. I originally liked it because of the lightweight of the unit but i ended up hating it and any hiker that wants to go on long distance hikes stay away from this product because it isn't if it will fail on you but rather when it will fail on you.
    Date published: 2014-01-09
    Rated1out of5byfromNot reliableI have taken this on many backpacking trips only to find that I can not get more than 2 to 3 filtrations per set of batteries. While the pen is lite, which is why I bought it in the first place, it is not just worth the headache, and in reality you are not saving any weight because of the amount of batteries you must carry to make this thing last over a course of a trip. It is easier and more reliable to take my Katadyn hand pump that way I know I have a filter that's going to work and filter sediment from the water. This to me is worth the little extra weight. When I go to Nepal the SteriPEN is staying home.
    Date published: 2014-01-06
    Rated4out of5byfromGreat for trip to South AmericaI got this for a trip to South America because I didn't want to drink only bottled water. It worked great the whole time.. the only problem is that you have to use it with a Nalgene or other large mouth so you can stir the pen in the water properly. It also took about 2 minutes at a time, which isn't a big deal. It saved a lot of plastic water bottles! I plan on using this when backpacking in the future.
    Date published: 2013-11-16
    Rated4out of5byfromSo far so good!We used our new Steripen for two weeks of backpacking and day-tripping on horse-heavy trails, and stayed healthy. But it's not like we did a test with one of us drinking untreated water. The pen is light and fast and leaves the water good-tasting. The only down-side is that the indicator lights are unpredictable from time to time.
    Date published: 2013-10-09
    Rated5out of5byfromLightweight & super straightforward!We used one of these on a backpacking trip thru the Enchantments. It purified everyone's water (6 people total) for almost three full days before it ran out of battery! And we were drinking and cooking A LOT. Insanely lightweight & compact, moreso than any other model I saw at REI. Plus the functionality is very straightforward and leaves little room for user error. No complaints! Very satisfied with this product.
    Date published: 2013-09-20
    Rated4out of5byfromWorks for meI have used on 2 backpacking trips. Was using a pump before. Nice product. Works as advertised. Beats pumping. The indicator lights are hard to read if you are not in the shade, which is why I don't give it 5 stars, but this is by no means insurmountable (audible beeps would be nice). Batteries aren't cheap. You get (per the mfr) about 50 liters per set. I am not sure how this compares to the cost of replacing filter cartridges or using tablets/drops, but seems pretty similar. I have only used on clear alpine water sources, not murky water. Even for clear water, the prefilter is nice (also helps keep the bottle lid dry)
    Date published: 2013-08-28
    Rated5out of5byfromBest invention since the bicycleIt's all in the title, this is the best thing since the bicycle. Better than bacon even. Used it on 3 backpacking trips so far and no problems at all. It's extremely easy to use and not hard to read, just keep the directions with you if you're easily confused by the lights. They fold up and fit nicely into the padded case. The lights are plenty easy to see in broad daylight if you look at them from the correct angle. I highly recommend!
    Date published: 2013-08-17

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