Effortless Installation& Perfect Fit for Standard Ducts Designed to fit 4 x 10-inch duct openings, these vent covers are compatible with most standard floor, wall, or ceiling vents. Installation is a breeze no screws or tools are required. ONLY MEASURE THE DUCT OPENING (the hole on the wall/ceiling) by measuring the WIDTH first, and then the HEIGHT, anyone can easily install it. Durable &Sturdy Construction Constructed from high-quality steel.The dual surface of the floor register is coated with a rust-resistant pre-coat, ensuring that your floor grille maintains its pristine appearance in any environment. Enjoy worry-free usage, even during the winter months. Adjustable Airflow for Optimal Comfort Our 4" x 10" floor vent covers featuring an opposed blade damper, allows you to easily adjust airflow for maximum comfort and energy efficiency.