This is an example of a United States Air Force tropical weight blue shade 1549 enlisted man's uniform. This style of uniform was introduced in 1967 and phased out of service in 1999.
This uniform was worn by the donor CMSgt. Donald Harlow (1920-1997). He served with the U.S. Army Air Forces and Air Force from 1942 until his retirement in 1971. He served throughout the world during his career ultimately becoming the Chief Master Sergeant of the Air Force serving at HQ USAF in Washington DC at the end of his service.