They didn't fit. But they were the size that was listed. My mistake was in assuming that if I ordered a 16x25x4, it would fit. Like a wood 2x4 isn't fully 2x4, the filter would fit. Not so. So I cut up the box they came in and glued 4" slats to three sides to bring them to size to fit. And I cancelled my automatic order program for yearly service. Also, the filter fabric (Merv13 according to markings) seemed to be thinner than the major manufacturers product I was replacing. And the accordion style form of the filter itself was hap hazard. No uniformity in spacing or evenness. Like they're made by hand, not machine. I'm using the ones I have, but will not be reordering.