You Gotta Have Faith
When I got this my son asked how we could know if it works.  I explained that we had no way of knowing, we just had to rely on what the manufacturer says and reviews.  I can't really say whether it works or not.  What I can say is that it is extremely loud.  The day after I plugged it in the kitchen, I walked in and thought that there was something wrong with my refrigerator because of the noise.  Then I realized that it was the germ guardian.
Rating: 3 stars