Original 1970 Seiko 6139-6010 proof/proof automatic chronograph advertisement commemorating the Japan World Exposition, Osaka, 1970 or "Expo '70," the world's fair held in Suita, Osaka Prefecture, Japan between March 15 and September 13, 1970.  Its theme was "Progress and Harmony for Mankind."
 
Dimensions: 10.25 inches wide by 13.5 inches high