Germany: Zeppelin airmail labels 2

Here are more rare airmail labels from Germany, intended for use on Zeppelin-mail.

Year: 6.1933, Gummed. Günter Mair's catalogue no: - GER-C-12a, imperforated, sheets of 10(2x5),
black/bright blue, 5*****

Year: 6.1933, Gummed. Günter Mair's catalogue no: - GER-C-12b, imperforated, sheets of 10(2x5),
black/white, 5*****

Year: 1936, Gummed. Günter Mair's catalogue no: - GER-C-19, imperforated, embossing,
intended for use on Zeppelin-mail, dark blue/white, 5*****