Guatemala: CNA airmail labels

 This is an airline issue label from CNA (Compania Nacional de Aviacion), Guatemala.

Year: 1932, Gummed. Günter Mair's catalogue no: - GTM - B - 1a, perforated 12 ½ , sheets of 30(3x10)
greenish blue or greenish grey-blue/red/white, 4****