KATTOWITZ, 20 Pfg blue Numeral issue 1920 as single franking on letter to Hruschau / Czechoslovakia, double-circle KATTOWITZ 24 2 20 * (OBERSCHL.) h (OS handbook No. 141.28), passed German currency control in Zittau: blue resealing strip and violet "20" (= Zittau, unlisted in OS handbook), age and use marks typical of period