I was skeptical about whether UV Sterilization really worked. Given all the hype about Covid-19 and publications about how dirty your phone is, I decided to try a sanitizer. I started looking at small units that would fit just the phone, but for the price, it seemed that this larger model would be a better idea. My plan was to test the unit and return it if it didn't really work. I also purchased at the same time "Nutrient Agar Plates" to grow bacteria. After receiving the unit, I was pleasantly surprised that the quality was reasonable. Not the quality of a high end microwave, but suitable for a $140 product. The first thing I did was take the Agar plate and marked 2 halves with a sharpie. I deposited a bacterial sample on one half and the immediately disinfected it with UV. I then deposited another bacterial sample on the other half. I let the bacteria grow for about a week. It did not grow on the sterilized half, but grew on the unsterilized half. For me this is good enough for me to trust the unit.