Filters work as advertised. The filter is mounted in the ceiling. When the fan starts the filter is sucked into the housing and drops down when the fan stops.
Received the filters promptly and they appear to work well. Only complaint is the fit is a bit off, as they are thinner than the unit, and bend slightly going in.
I receive them timely and undamaged. I can't tell how well they work but I can tell they are substantially better quality in design and execution than those grocery store brands. It really IS going to filter versus just fill that space. I have happy and feel I have made a good decision for my air quality!