8" X 8" [Duct Opening] 1-Way Air Vent Adjustable Aluminum Curved Blades Integral Multi-Shutter Damper HVAC Diffuser [Outer Dimensions: 9.75"W X 9.75"H] Compatible With Duct 12in Designed for a 1" thick 4 X 12 Is CRFG2028 Width_14in

Designed for a 1" thick filter

+ Product Details Size - 25"w X 22"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

+ Product Details Size - 34"w X 16"h is the size for the duct opening measurement only

Installation Location – Ceiling

8" X 8" [Duct Opening] 1 Way Air Vent Adjustable Aluminum Curved Blades Integral Multi Shutter Damper HVAC Diffuser [Outer Dimensions: 9.75"W X 9.75"H] Compatible With Duct 12in Designed for a 1" thick 4 X 12 Is CRFG2028 Width_14in Designed for a 1" thick filter + Product Details Size 25"w X 22"h is the size for the duct opening measurement only