Filter size is a little too tight. It is difficult to push the filter along the tracks to get it into the correct position. MA few filters have torn when I slide them on the track.
I have just one problem with the MERV filter....having to write a review on it. But I keep being bugged with emails to do so. It's a filter. What more can one say? It's not like it performs any activity that can be watched and judged. It filters. That's it.