16" X 20" Steel Return Air Filter Grille for 1" Filter - Removable Frame - [Outer Dimensions: 18 5/8" X 22 5/8"] Copper Coil accordion-content { display: block

accordion-content { display: block

Actual Filter Size – 13 3/4"w x 24 3/4" x 1"

1/2" White insulation will give you a good R value of 3

+ Product Details Size - 30"w X 26"h is the size for the duct opening measurement only

+ Product Details Size - 25"w X 24"h is the size for the duct opening measurement only

16" X 20" Steel Return Air Filter Grille for 1" Filter - Removable Frame - [Outer Dimensions: 18 5/8" X 22 5/8"] Copper Coil accordion-content { display: block+ Product Details Size 16"w X 20"h is the size for the duct opening measurement only, actual front end outer dimensions are approximately 18 5 8" width X 22 5 8" height Actual Filter Size 15 3 4"w x 19 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.