34" x 28" Cube Core Eggcrate Return Air Filter Grille for 1" Filter d + Product Details Perfect Fit 4 X 12 Is CRFG2028 Width_14in

+ Product Details Perfect Fit & Easy Sizing - Designed for a 34" x 28" Or 28" x 34" duct opening (measured at the opening)

+ Product Details Perfect Fit & Easy Sizing - Designed for a 22" x 36" OR 36" x 22" duct opening (measured at the opening)

+ Product Details Size – 25"w X 12"h is the size for the duct opening measurement only

actual front end outer dimensions are approximately 20 5/8" width X 38 5/8" height -

+ Product Details Perfect Fit & Easy Sizing - Designed for a 32" x 16" OR 16" x 32" duct opening (measured at the opening)

34" x 28" Cube Core Eggcrate Return Air Filter Grille for 1" Filter d + Product Details Perfect Fit 4 X 12 Is CRFG2028 Width_14in + Product Details Perfect Fit & Easy Sizing Designed for a 34" x 28" Or 28" x 34" duct opening (measured at the opening) + Product Details Perfect Fit & Easy Sizing Designed for a 22" x 36" OR 36" x 22" duct opening (measured at the opening)