14" X 20" Or 20" X 14" Heavy Duty Floor Grille - Fixed Blades Air Grille - Brown [Outer Dimensions: 15.75 X 21.75] Ceiling + Product Details 18" x 4 X 12 Is CRFG2028 Width_14in

+ Product Details 18" x 18" x 1" replacement air filters for your furnace

and a control lever designed for seamless operation

+ Product Details Size - 28"w X 28"h is the size for the duct opening measurement only

Actual Filter Size – 9 3/4"w x 35 3/4" x 1"

+ Product Details Size & Compatibility – The size of sheet metal pipe is 6" round x 60" long

14" X 20" Or 20" X 14" Heavy Duty Floor Grille Fixed Blades Air Grille Brown [Outer Dimensions: 15.75 X 21.75] Ceiling + Product Details 18" x 4 X 12 Is CRFG2028 Width_14in + Product Details 18" x 18" x 1" replacement air filters for your furnace and a control lever designed for seamless operation