Not the one to buy.
I bought two. I can't smell any ozone at all with my nose right against it running full blast.  These are small pucks about 3" diameter 1/2" thick, and they look good but don't work well. Not at all. I bought two of the O3 Pure brand units as well. They are cubes about the size of a coffee mug laid on its side. Bigger, but they work for a month instead of a week, and they are 10X as much ozone production by the specs, and they work fantastically. I got those from e-bay though, angry at Amazon for refusing to tell me where they are from. All four of these that I bought are from China. I'm happy for a good product with the O3 Pure Refrigerator Purifier, but this particular one is junk in my book.
Rating: 2 stars