16" x 18" or 18" x 16" Cube Core Eggcrate Return Air Filter Grille for 1" Filter return grille actual front end outer dimensions 4 X 12 Is CRFG2028 Width_14in

actual front end outer dimensions are approximately 10 5/8" width X 30 5/8" height

actual front end outer dimensions are approximately 26 5/8" width X 24 5/8" height

+ Product Details Perfect Fit & Easy Sizing - Designed for a 34" x 12" Or 12" x 34" duct opening (measured at the opening)

actual front end outer dimensions are 21

and utility rooms

16" x 18" or 18" x 16" Cube Core Eggcrate Return Air Filter Grille for 1" Filter return grille actual front end outer dimensions 4 X 12 Is CRFG2028 Width_14in actual front end outer dimensions are approximately 10 5 8" width X 30 5 8" height actual front end outer dimensions are approximately 26 5 8" width X 24 5 8" height