12"w X 12"h [Duct Opening] 4-Way Fixed Curved Blade Air Supply Diffuser Register Vent Cover Grille [Outer Dimensions: 13.75"W X 13.75"H] w8h8 actual front end outer dimensions

actual front end outer dimensions are approximately 36 5/8" width X 24 5/8" height

order a 20x14

and with a built-in back 1/2" mesh they also protect you from annoying rodents like mice

+ Product Details Size - 18"w X 12"h X 2"d (for duct opening measurement only)

12"w X 12"h [Duct Opening] 4-Way Fixed Curved Blade Air Supply Diffuser Register Vent Cover Grille [Outer Dimensions: 13.75"W X 13.75"H] w8h8 actual front end outer dimensions+ Product Details Size 12"w X 12"h is the size for the duct opening measurement only, actual front end outer dimensions are approximately 13. 75" width X 13. 75" height. High Quality High quality steel with counter sunk screw holes (screws included) and no sharp edges. Equipped with a lever for easy airflow adjustment and dampening. Airflow Control Adjustable airflow lever allows precise control over the direction and volume of air. Installation