First Day of Issue = September 5, 1933
Size: 37.00 mm x 23.00 mm
Quantity printed = 8,420
Perforated 11.50 x 11.50
Print method: Lithography

The surtax was for wounded Latvian aviators. The stamp shows a Graf Zeppelin over Riga.

Watermark



Catalog numbers
Scott CB23
Michel LV 230A

For more information check out the links below
Graf Zeppelin
Latvian airmail semipostal stamps
Latvian aviation