The steripen is awesome. I took it backpacking for the first time a couple of weeks ago and I have to say that this is probably my best investment for backpacking equipment I have ever made. The pre filter works better than I expected, and as I watched my friends use their pump filters I was watching the river roll by while using the UV light to kill any thing that could make me sick. My steripen took less time to get the job done and was a lot more portable. Everyone wanted it for day hikes. Best tool I own.