This White 20" x 10" Shoemaker 935-0 Series Vent Cover is designed to fit and cover a 20" wide by 10" high opening. Shoemaker has a complete line of products designed for homes, offices, stores, and many other commercial applications. The quality and simplicity of this Fixed Blade Grille are only two of the many reasons why Shoemaker Manufacturing leads the field in innovative air-grille design for real world applications. The Shoemaker 935-0 Series Steel Blade Grille with 45° Fixed Blade is designed with steel rigid bar louvers at 45° that are parallel to the longest dimension, allowing a minimal view of the air duct. For a smooth appearance, it has countersunk mounting holes with Phillips posi-drive screws with colors that match the vent cover. The Shoemaker 935-0 Series vent cover comes with a recessed screwdriver-operated opposed blade damper. It is used to regulate the airflow through linked sections of adjacent blades that rotate in the opposite direction. Compared to other damper types, an opposed blade damper maintains a more even airflow. It also provides better control over the airflow in all operating positions. A recessed screwdriver-operated damper prevents any unnecessary adjustments of the damper setting. Normally, vents covers are mounted in walls but this can be mounted in ceilings as well. The standard color of this grille is soft white. The Shoemaker 935-0 Steel Blade Grille can be ordered with "F" Torx center pin tamper-proof screws for added security. Be sure to measure the hole opening size instead of measuring the face plate of your old grille. This grille is designed to fit over a 20" x 10" existing hole or duct. Refer to the Specification Sheet for more information.