1923 Sc 9-12 Air Mail Scott C2-C5

1923. Air Mail.
Catalog numbers: Scott C2-C5, Standard Collection 9-12, Michel XV-XVIII, Yvert PA10-PA13.
Issued on: August 8, 1923.
Perforation: Imperforate.
Printing: Lithography.
Colors: Multicolor.
Face value: 1 ₽; 3 ₽; 5 ₽; 10 ₽.
Quantity: 18,000; 18,000; 18,000; 18,000.