12" X 10" [Duct Opening] 2-Way Horizontal Fixed Curved Blade Air Supply Diffuser Register Vent Cover Grille [Outer Dimensions: 13.75"W X 11.75"H] Round Damper Ring Actual Filter Size – 7 4 X 12 Is CRFG2028 Width_14in

Actual Filter Size – 7 3/4"w x 19 3/4" x 1"

+ Product Details Size – 16"w X 26"h is the size for the duct opening measurement only

+ Product Description Introducing the 8" Radial Damper – Your Solution for Controlled Airflow

+ Product Details Size – 12"w X 30"h is the size for the duct opening measurement only

High Quality – Heavy-gauge all-steel construction

12" X 10" [Duct Opening] 2 Way Horizontal Fixed Curved Blade Air Supply Diffuser Register Vent Cover Grille [Outer Dimensions: 13.75"W X 11.75"H] Round Damper Ring Actual Filter Size – 7 4 X 12 Is CRFG2028 Width_14in Actual Filter Size – 7 3 4"w x 19 3 4" x 1" + Product Details Size – 16"w X 26"h is the size for the duct opening measurement only