8" X 20" Steel Return Air Filter Grille for 1" Filter - Removable Frame - [Outer Dimensions: 10 5/8" X 22 5/8"] Grille + Product Details Size – 4 X 12 Is CRFG2028 Width_14in

+ Product Details Size – 24"w X 20"h is the size for the duct opening measurement only

+ Product Details Size - 34"w X 12"h is the size for the duct opening measurement only

75" width X 27

+ Product Details Size – 12"w X 18"h is the size for the duct opening measurement only

3/8" - 4223 PSI

8" X 20" Steel Return Air Filter Grille for 1" Filter Removable Frame [Outer Dimensions: 10 5 8" X 22 5 8"] Grille + Product Details Size – 4 X 12 Is CRFG2028 Width_14in + Product Details Size – 24"w X 20"h is the size for the duct opening measurement only + Product Details Size 34"w X 12"h is the size for the duct opening measurement only