Product review (5 stars): does what it's meant to do
Not a lot to say about this other than it does what it's supposed to do. Cannot reliably review length of usefulness, as ours functions as a air purifier gathering cat hair. I'm sure that probably reduces it's life.

When the filter indicator goes red, I let the filter completely dry. I gently remove the layer of cat hair, soak it in vinegar, rinse and use it again for a while. After being cleaned, the indicator goes back to blue.