12" X 34" Steel Return Air Filter Grille for 1" Filter - Removable Frame - [Outer Dimensions: 14 5/8" X 36 5/8"] 8" Diameter + Product Details Size –

+ Product Details Size – 8" x 30" or 30" x 8" is the size for the duct opening measurement only

+ Product Details Size – 8"w X 24"h is the size for the duct opening measurement only

+ Product Details Perfect Fit & Easy Sizing - Designed for a 10" x 20" duct opening (measured at the opening)

+ Product Details Size – 18"w X 25"h is the size for the duct opening measurement only

actual front end outer dimensions are approximately 18 5/8" width X 28 5/8" height

12" X 34" Steel Return Air Filter Grille for 1" Filter - Removable Frame - [Outer Dimensions: 14 5/8" X 36 5/8"] 8" Diameter + Product Details Size –+ Product Details Size 12"w X 34"h is the size for the duct opening measurement only, actual front end outer dimensions are approximately 14 5 8" width X 36 5 8" height Actual Filter Size 11 3 4"w x 33 3 4" x 1" High quality High quality solid stamped steel with counter sunk screw holes (screws included) and no sharp edges Location Sidewall and ceiling Design Removable door face for easy filter change & cleaning uses a 1" thick filter. Our filter