A-Frame Sidewalk Sign with 2 Display Options: Snap-Open Holders for 23.75" x 33.5" Poster Boards or Black Magnetic Inserts - Aluminum, Black For indoor or outdoor use. Aluminum snap-open frame design holds two 23-3/4 x 33-1/2-inch sign panels up to 3/16-inches thick. Includes 2 removable and magnetic gloss black steel inserts that can be used with vinyl letters or magnets. A hinge on top allows the sidewalk sign to fold down to 3-1/4-inches thick, making it easy to store. Displays2go SKU#: AFBKBRD2S2