Product review (3 stars): OK, but weak evaporation performance
The good news is that the product I received is the product that is pictured. Some other reviewers said that this was not the case for them.

The bad news is that this filter is rather small in diameter and thin, and its performance reflects these deficiencies. My Honeywell HCM535 humidifier ran almost constantly when I used this filter during November-December, struggling to maintain 50% humidity. I maintain my humidifier properly by using bacteriostat in the tank and by periodically flipping over the filter to suppress scale buildup.

In contrast, I recently switched to the Sunbeam size "B" replacement filter (model SF213), and now my humidifier can easily maintain 50% humidity while running only about half of the time. I had to modify the Sunbeam filter by cutting about 1.5 inches off the top.

If you use your humidifier for a single closed room, the BestAir filter may still work for you. I use mine for an entire 2000 sq. ft. house, and for this purpose there are definitely other filters that perform better.