36" X 20" Steel Return Air Filter Grille for 1" Filter - Fixed Hinged - [Outer Dimensions: 38 5/8" X 22 5/8"] Insulated Line Set + Product Details Size – Product Description Enhance your CRFG68 Victorian Floor Registers

+ Product Details Size – 4"w X 12"h is the size for the duct opening measurement only

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

7/8” - 3397 PSI

For example

+ Product Details Size - 24"w X 2"h is the size for the duct opening measurement only

36" X 20" Steel Return Air Filter Grille for 1" Filter Fixed Hinged [Outer Dimensions: 38 5 8" X 22 5 8"] Insulated Line Set + Product Details Size – Product Description Enhance your CRFG68 Victorian Floor Registers + Product Details Size – 4"w X 12"h is the size for the duct opening measurement only actual front end outer dimensions are approximately 12 5 8" width X 12 5 8" height