A British auction house says it's selling a rare U.S. stamp that was printed upside down.
The 1918 inverted Jenny stamp is one of stamp collecting's most famous prizes.
The stamp is expected to fetch more than US$200,000 when it is sold on Wednesday.
The 24-cent air mail stamp features a Curtiss JN-4 Jenny biplane, but was mistakenly printed upside down. Only 100 of the red, white and blue stamps were printed.
Auctioneers said the stamp is being sold by a British collector and is the first time in 50 years that one of the stamps has been sold outside of the U.S.
An inverted Jenny sold in New York in October for US$388,125.