50 C. Mercury head, vertical pair from the left margin of the sheet with overprint "Occupied Territory Northern France" in Type I, appropriate multiple franking on a letter from "Ghyvelde 22. 07. 1940" to Dunkerque with a reverse arrival stamp dated 23. 07. 1940, flawless condition, certified by Pickenpack, expertise by Lothar Herbst VP (2025) "The condition is impeccable. The stamps are known in very small quantities, therefore they are rare.", Michel 600.-