Grille filters can be hard to find and have odd actual sizes, lucky for you our job is to make replacement filters easy. You will find with most "Grille" cut filters the larger dimension will be listed first, and if you were to take the actual measurement it's likely 7/8" smaller than what is printed on the filter. On the short side most likely 5/8" smaller. Many makes and models of Grille filters have been discontinued by manufacturers over the years making them harder to find. The "Grille" filters we carry are the recommend replacements made by AAF Flanders.