Keep your customers safe with our easy to use, affordable Caution Face Masks Required Window Decal. This decal is oriented horizontally. This decal is 12″ x 7″, which is a perfect size for your store window or glass door; large enough to attract attention but doesn’t take up too much “real estate.” These decals are easy to install. You can install it yourself in minutes. This decal mounts to the outside of the window to allow for maximum visibility.