SteriPEN Adventurer Opti Put to the Test!

SteriPEN Adventurer Opti

The SteriPEN Adventurer Opti is the newest in the lineup of SteriPEN UV water treatment products. I have been using my SteriPEN Classic on every backpacking adventure since I first got it a few years ago, and absolutely love it. (Check out my review of my SteriPEN Classic and my article Hiking 101: Water Treatment for more info on water treatment.

When I was asked if I’d like to test out the new SteriPEN Adventurer Opti, I jumped at the chance! I had always been hoping that the innovative team at SteriPEN would come out with an even lighter weight and smaller SteriPEN, and this weekend I got to put it to the test.

I did a long (very long…) day hike to Mt. Baldy here in Southern California (it actually was more of a mountaineering trip since there is still snow and ice on the trail and I had to use an ice axe and crampons!), and I decided that I’d treat some water at the spring next to the ski hut 2.5 miles up the trail. I attached the SteriPEN Prefilter to my Nalgene bottle, filled it up with water, pressed the activation button, waited a couple of seconds for the indicator light to flash, then put the Adventurer Opti in my Nalgene and stirred it around (just like stirring a beverage!). My SteriPEN Classic fits through the PreFilter, but when using the SteriPEN Adventurer I had to remove the PreFilter.
SteriPEN Prefilter
Quick Hiking Lady Tip: I’d highly recommend getting the SteriPEN Prefilter. When I bought my SteriPEN Classic, the Prefilter was included in the package. I haven’t seen them included in the Adventurer Opti, so if you don’t have one already this is what they look like:

How the SteriPEN Opti Adventurer compares to the SteriPEN Classic:

    • Weight: Even lighter! The Adventurer is 103 grams (3.6oz) including batteries! It feels noticeably lighter than the 162g (5.7oz) Classic.
    • Size: Even smaller! The Adventurer is just 15.5cm (6.1 inches long), which is shorter than the Classic by more than an inch. The grip has a nice rubberized feel.
    • Speed & Effectiveness: Equal. The UV light of the SteriPENs kills protozoa, bacteria, AND viruses (filters can’t kill viruses) in 90 seconds.
The flashlight feature of the SteriPEN Adventurer Opti
The flashlight feature of the SteriPEN Adventurer Opti
  • Other features: Adventurer wins out! I love when my gear can serve multiple functions, and the Adventurer Opti can be used as a flashlight! The flashlight provides a nice beam as a backup. I’ll still be hiking with my headlamp, but a backup flashlight is always great to have.

The only feature that I really like about my SteriPEN Classic where the SteriPEN Adventurer Opti falls short is that it requires 2 CR123 batteries, whereas my Steripen Classic takes 4 AAs. Clearly 2 batteries are better than 4, and that is what makes the Adventurer Opti so light, however, AAs tend to be more versatile on the trail than CR123s. Many headlamps, GPSs and cameras use AAs. Plus CR123s are a little pricier than AAs.

The SteriPEN Adventurer Opti is $20 more than the Classic. If you don’t have a SteriPEN yet, I’d highly recommend paying the extra $20 for the Opti. If you already have a SteriPEN Classic or the older version of the Adventurer or one of SteriPEN’s other models, I don’t think a trade up to the new version is justified (unless you’re an ultralight backpacker and want to shave off 2.1oz.

Since my SteriPEN Classic is my most borrowed piece of gear, I am going to recommend to my friends to get SteriPEN Adventurer Optis for themselves 🙂

My How To Video: How to Use a SteriPEN to Treat Water:



Also check out this great question from a Hiking Lady reader: Does the SteriPEN pre-filter keep the Nalgene threads bacteria free?

See More Hiking Gear Reviews:

Essential Gear
Essential Gear

Apparel Reviews
Apparel Reviews

Footwear Reviews
Footwear Reviews


  1. Hiking Lady says:

    Hi Emily,
    The company doesn’t recommend it, and if you were to treat the water in a Camelbak you’d only be able to do a liter at a time. So after the first liter is treated, you’d still need a separate container to treat the next liter before adding it to your Camelbak. Hope that helps!

  2. Emily Cross says:

    I;m thinking of purchasing one of these. Can you do this treatment in your Camelbak water bag as opposed to carrying a Nalgene?

  3. Hiking Lady says:

    Hi Marco,
    Yep, I realize a lot of people who are really ultra-light backpackers do not even carry Nalgene’s because of their weight. I like to carry one Nalgene because it is sturdy, easy to fill in a stream or creek, and easy to zap with my SteriPEN Classic or SteriPEN Opti. I cut my ounces in other areas 🙂
    Thank you for the great comment. Happy trails!

  4. Marco says:

    The problem with the Steripen Opti is that it’s harder to find suitable 1 ltr UL water containers for it. The hard Nalgene polycarbonates are way too heavy. Everyone I know uses UL recycled water bottles (e.g. aquafina, ethos, etc.) that have a narrow mouth that does not work with the Steripen. The Journey + typical water bottle weigh 5.60 oz. The Opti + hard Nalgene weigh 9.85 oz. With the Classic, add about one more oz.

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