20" x 25" Cube Core Eggcrate Return Air Filter Grille for 1" Filter - Aluminum - White [Outer Dimensions: 22.5"w X 27.5"h] Aluminum - Cube Core look no further than HVAC 4 X 12 Is CRFG2028 Width_14in

look no further than HVAC Premium

+ Product Details Size - 28"w X 10"h is the size for the duct opening measurement only

actual front end outer dimensions are approximately 14 5/8" width X 14 5/8" height

+ Product Details Perfect Fit & Easy Sizing - Designed for a 12" x 12" duct opening (measured at the opening)

only measure the "hole" in the wall/duct

20" x 25" Cube Core Eggcrate Return Air Filter Grille for 1" Filter Aluminum White [Outer Dimensions: 22.5"w X 27.5"h] Aluminum Cube Core look no further than HVAC 4 X 12 Is CRFG2028 Width_14in look no further than HVAC Premium + Product Details Size 28"w X 10"h is the size for the duct opening measurement only