Blue Pure 311 Auto Series Particle + Carbon Filter

seems good

Filter fits my 311-Auto unit like the original. Seems to do the job. My only complaint is about the unit itself. I find it frustrating that I cannot remove the top grill to clean it. I think that is a real flaw in the design.

Blue Air Filter

I replaced a very filthy filter due to our recent floor refinishing project. It’s good to know so much of the dust was trapped!

Amazing fikter

I change the filter 3 times a year. I live in the upper west side of NYC The filter is black when I change it. Thank God these were invented!