The United States Air Force came into existence in 1947. The distinctive flag background color of the Air Force was established in 1951. The flag background is a special shade known as Air Force blue. The central shield has a stylized thunderbolt symbol of the kind used in the Roman Empire. The blue shield appears over white clouds known in heraldry as nebuly. The ring of 13 stars refers to the original states of the nation. A bald eagle, the national bird, stands at the top with its wings spread. Behind its head is an area of clouds similar to those appearing in the coat of arms of the United States. Suitable for Parades or Indoor Display, Annin Flagmakers Colonial Nyl-Glo Flag is made of 100% Nylon and trimmed with two inch gold rayon fringe. The flannel lined pole hem sleeve slides over a standard 1 ¼ inch diameter pole, and attaches by an inner tab. This flag is 100% Made in the USA to Official Specifications. The indoor/parade 3X5' size flag is designed to display with an 8' mounting pole.