16" X 16" Steel Return Air Filter Grille for 1" Filter - Removable Frame - [Outer Dimensions: 18 5/8" X 18 5/8"] w8h8 accordion dd { margin: 0

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The total outer size of this grille is the listed size plus 1

This thoughtful design ensures optimal air circulation for your HVAC system

+ Product Details Size - 4"w X 26"h is the size for the duct opening measurement only

+ Product Details Size - 16"w X 8"h is the size for the duct opening measurement only

16" X 16" Steel Return Air Filter Grille for 1" Filter - Removable Frame - [Outer Dimensions: 18 5/8" X 18 5/8"] w8h8 accordion dd { margin: 0+ Product Details Size 16"w X 16"h is the size for the duct opening measurement only, actual front end outer dimensions are approximately 18 5 8" width X 18 5 8" height Actual Filter Size 15 3 4"w x 15 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.