I ordered two 20X24X4 filters and received filters with different "actual" measurements. The fit is not as good and I don't expect the filters to perform as well as ones that "actually" fit. I didn't read the fine print, I guess, though not sure why there should be fine print for a simple furnace filter.
These are a 4 inch filter but are in fact about 3 and 5/8 inches. So as a replacement for a Honeywell 4 inch filter which measures 4 plus inches, it leaves something to be desired.