Editors' Choice 2011: SteriPEN Adventurer Opti - Backpacker

Editors' Choice 2011: SteriPEN Adventurer Opti

This ultralight water purifier is fast, easy, and leaves zero aftertaste.

Our testers have tried every water-treatment method available, and for most trips and most conditions, this one beats them all. Why?

1) It’s half the weight of the lightest filter.

2) It’s much faster than chemical treatments (90 seconds for a liter, compared to 30 minutes to four hours).

3) It doesn’t change the taste of delicious alpine water.

4) It eliminates all microorganisms (bacteria, protozoa, and viruses), making it a great choice for North American wilderness and developing countries alike. In short, it’s near-perfect for almost all backcountry water treatment. SteriPEN has been perfecting the use of ultraviolet light—a proven purification method long used by municipal water-treatment facilities—in portable, handheld devices for a decade, and this unit is the lightest and most reliable yet, which is why it has cleared the bar to earn our highest award.

During almost a year of testing, from the Rockies to California’s Trinity Alps to Capitol Reef to New Zealand’s busy tracks, the Adventurer never failed. Not once. Simply push the single button (once for a liter, twice for a half liter), dunk the wand into your water bottle, and gently stir until the green light comes on. Then drink up.

The Adventurer’s new optical sensor has had no trouble with even icy snowmelt (and it doubles as an emergency flashlight). According to SteriPEN, two CR123 batteries treat up to 100 liters, and the UV bulb lasts for 8,000 treatments. Caveats: You need a widemouthed bottle to dip in, and it’s not the best choice for turbid water (a $15 prefilter is sold separately). $100; 3.8 oz. (with batteries); steripen.com