21" x 40" magnetic garage banner for steel garage doors with 21" sections. Most garage doors are made of steel. But you should check your door with a magnet before purchasing to make sure it is steel. Made entirely in the USA in a Veteran Owned and Operated company. This magnetic product really makes your garage stand out. Dress up your steel garage door with this beautiful magnetic US Flag. This large 21" x 40" magnetic flag is designed to fit in one section on most standard steel sectional garage doors. Because it is magnetic it stays put when you open and close the garage door. Unlike other garage door banners, no other parts have to be purchased. Simply unroll, line it up with the section, and smooth it out. Surface should be clean before attaching. The images show the flag (banner) attached to the most common garage door sizes; 8 feet and 16 feet by 7 feet high. Printed with UV inks, these banners resist fading.