EZ-FLO 61656 Steel Return Air Filter Grille for Sidewall and Ceiling Installation with Screws, 18" x 18" White FINISH: White Powder-Coated Smooth Finish quickly updates any room or office DIMENSIONS: Duct Opening: 18-inch x 18-inch sidewall or ceiling mount, The outer Dimension measures 20-11/16 x 20-11/16 inches MATERIAL: All steel construction; high-impact, heavy-duty steel makes this air vent filter grille highly durable CONTENTS: This package includes a kit of screws to make installation easy and efficient EASY INSTALLATION: This return filter grille can be installed on the sidewall or ceiling without any hassle to ensure maximum airflow