36" x 34" Cube Core Eggcrate Return Air Filter Grille for 1" Filter sidewall + Product Details Size - 4 X 12 Is CRFG2028 Width_14in

+ Product Details Size - 12"w X 16"h X 2"d (for duct opening measurement only)

actual front end outer dimensions are approximately 27 5/8" width X 12 5/8" height

+ Product Details Perfect Fit & Easy Sizing - Designed for a 26" x 18" OR 18" x 26" duct opening (measured at the opening)

+ Product Details Size – 10" x 22" or 22" x 10" is the size for the duct opening measurement only

+ Product Description Upgrade your HVAC system with a high-quality aluminum return grille designed for a clean

36" x 34" Cube Core Eggcrate Return Air Filter Grille for 1" Filter sidewall + Product Details Size 4 X 12 Is CRFG2028 Width_14in + Product Details Size 12"w X 16"h X 2"d (for duct opening measurement only) actual front end outer dimensions are approximately 27 5 8" width X 12 5 8" height