36"W X 12"H [Duct Opening] ALUMINUM RETURN GRILLE - Easy Air Flow - Linear Bar Grilles [Outer Dimensions: 37.875"W X 13.875"H] Color_Aluminum Actual Filter Size – 13 Suitable for all AC 8in diameter 12125SDCLNGBX

Actual Filter Size – 13 3/4"w x 19 3/4" x 1"

+ Product Details Size - 14"w X 8"h is the size for the duct opening measurement only

+ Product Details Size - 20"w X 4"h is the size for the duct opening measurement only

this guard fits almost any thermostat and blends seamlessly into any setting

36"W X 12"H [Duct Opening] ALUMINUM RETURN GRILLE Easy Air Flow Linear Bar Grilles [Outer Dimensions: 37.875"W X 13.875"H] Color_Aluminum Actual Filter Size – 13 Suitable for all AC 8in diameter 12125SDCLNGBX Actual Filter Size – 13 3 4"w x 19 3 4" x 1" + Product Details Size 14"w X 8"h is the size for the duct opening measurement only