AAF Flanders 12 in. W x 18 in. H x 1 in. D Fiberglass 4 MERV Air Filter (Pack of 12)
Filter do not fit in the returns.
The filters do not easily fit in the returns. They cannot only be left on the surface. If you try to push them further they buckle cause if the frame and fiberglass to break. I don’t understand this since, since I have been using same brand from Home Depot with no problems.