For indoor use only. Enclosed Wood Look Changeable Letter Boards have a Wood-Look finish that is a unique powder coated process that combines the warm rich appearance of natural hardwood with the rugged and enduring qualities of extruded aluminum. Felt fixed rear panels are designed to accommodate changeable letters with tabs spaced on 1/4? centers. Standard features include: Lockable doors, acrylic safety glass windows, continuous hinges, concealed mounting brackets and a felt covered grooved panel. Includes a set of 165 count - 3/4" Helvetica letters.