Steri Pen

I used the Steri-pen for a week in the boundary waters with a group. I treated about 5 gallons a day (20 liters) and didn't have any problems. I also used it in yosemite on snake dike so I could carry less water. It has worked flawlessly for me. I do highly recommend the prefilter and I recommend using lithium batteries. Normally I use rechargeable batteries for shorter trips, but for my week in the boundary waters, I used lithium batteries and they didn't start to die til the last day.

My favorite benefits of the steripen are that it doesn't affect the taste of the water at all, it's fast (about 90 seconds), there's no pumping, and it's pretty light.

I carry iodine or chlorine dioxide as a back up and I carry a spare set of batteries, with that, I don't think you can go wrong.

this summer i was in the backcountry for over a month and the batterys died on my group alot looks cool works very fast but carry idione as backup. also deasnt work in cloudy water

if you are using this as a main source for water purification dont be surprised when you get the beavers if the water is just a little bit cloudy the steri pens dont work, it works great for filtering tap water and things like that but dont trust it as your only source for water in the backcountry.

Seriously, it's so light and much easier and smaller than the traditional water filter. It works very well, holds a good charge, and even fits in my pocket, kind of. Being an employee at REI I got mine at the prodeal price of $39.99, but hadn't I'd still say that it was well worth the pricetag.