Sweden. (Universale Postal Union). 1924. Registered envelope headed 'Congres Postal Universel Stockholm 1924' addressed to France bearing U.P.U. Yvert 175, 1k green, Yvert 176, 2k red and Yvert 175, 5k blue tied by Stockholm/ Congrees Postal Union double ring '31st July 24' with matching registered label and Montlucon arrival on reverse. Rare item.