United States Air Force (USAF) Challenge Coin. Master Sergeant United States Air Force. Size approximately 1 5/8 inches across. Worn condition. Additional Notes: A challenge coin is a small coin or medallion, bearing an organization’s insignia or emblem and carried by the organization’s members. Traditionally, they might be given to prove membership when asked. They are also collected by service members. Historically, challenge coins were presented by unit commanders in recognition of special achievement by a member of the unit. They could also be exchanged in recognition of visits to an organization. See Additional Information for shipping dimensions.
