20" X 34" Steel Return Air Filter Grille for 1" Filter - Removable Frame - [Outer Dimensions: 22 5/8" X 36 5/8"] w18h18 + Product Details Size –

+ Product Details Size – 12"w X 24"h is the size for the duct opening measurement only

is fireproof and ensures efficient thermal performance

+ Product Details Size – 18"w X 26"h is the size for the duct opening measurement only

+ Product Details Size - The listed 5" diameter refers specifically to the size of the duct opening

20" X 34" Steel Return Air Filter Grille for 1" Filter - Removable Frame - [Outer Dimensions: 22 5/8" X 36 5/8"] w18h18 + Product Details Size –+ Product Details Size 20"w X 34"h is the size for the duct opening measurement only, actual front end outer dimensions are approximately 22 5 8" width X 36 5 8" height Actual Filter Size 19 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 Installation Location Sidewall and ceiling Design Removable door face for easy filter change & cleaning uses a 1" thick filter.