Best thing I have done for my heating system. The Sheetmetal contractor had made a 2" filter slot but only reqd 1" filters. Put this new 2" filter in and the air flow out into the rooms increased greatly. Furnace is a lot quieter.
This is the first purchase of this particular filter, so I'm not in the position to evaluate its performance yet. I'll change it in three months and analyze it at that point as to what it took out of the air.