20 Kc. Airmail stamp with overprint "Karlovy Vary 1. X. 1938 plus swastika" on faultless letter piece with centered cancellation Karlovy Vary 1 4. X. 38 4 d, issued only 18 examples - one of the large rarities the Sudeten territory philately, expertise Robert Brunel VP (2021) "the condition is perfect. Very rare", Michel 3.500.-