Selling a Vintage 1930's Postcard featuring United Airlines The Mainliner Air Express Jet Plane. The postcard is in a "used" condition and has some age discoloration marks and curling along the edges. The back has been written on and postmarked. It measures approximately 5  3/8" x 3  1/4". Please feel free to message me with any questions or requests for more photos. Selling as is as shown in photos and description. Thanks