Sweden: Zeppelin airmail labels

Here are some airmail labels from Sweden intended for use on Zeppelin-mail.

Year: 1932, Gummed. Günter Mair's catalogue no: - SWE-C-1b, perforated 11 ½, sheets, 
Black/light grey-blue, 4****

Year: before 5.1936, Gummed. Günter Mair's catalogue no: - SWE-C-3a, perforated H 10 ¾, 
Vertical strips of 4, black/grey-blue, 4****

Year: approx.1930, Gummed.  Günter Mair's catalogue no: - SWE-C-3a, perforated H 10 ¾, 
Vertical strips of 4, black/grey-blue, intended for use on night airmail, 4****