Bought one and used it on a trip to Tenaya Canyon in Yosemite. I was able to get my first batch of water done which was 32 ounces. After that it was futile!!!! My buddy finally brought over his filter after 15 minutes of me trying to get a successful sign from my Steripen. Loads of cursing and such went on that is for sure. Luckily I used my buddies filter. I did carry Aqua Mira just in case. I went back to REI and returned it with no box or reciept. No questions asked!!!!

Today I bought the MSR Hyperflow. Hopes this does the trick. Looks quite nice!!