The 210VM series is 1-way air register used for wall or ceiling openings. The adjustable vertical front bars allow for 1-way airflow. Our Smooth glide technology ensures rattle free and quiet airflow from your central air system. Smooth glide also provides for smooth opening and closing of your back dampers. Our high-quality product will ensure years of continuous use. Product features: Adjustable vertical blades, Solid Steel Construction, White power-coat finish, Recessed screw holes, beveled edges.. Wall or ceiling register controls airflow into a room. Made of high quality steel. White powder coat finish. Smooth glide damper controls the amount and direction of airflow. Duct opening measurement. Width x height. Adjustable vertical blades. Maximum Duct Opening Length (in.): 8. Maximum Duct Opening Width (in.): 12. Installation Location: Wall. Installation Location: Ceiling. Decorative: No