1944 Sc 800-801 Airmail overprints Scott C80-C81

1944. Airmail overprints.
Catalog numbers: Scott C80-C81, Standard Collection 800-801, Michel 899-900, Yvert PA70-PA71.
Issued on: April, 1944.
Perforation: line 12¼.
Printing: Photogravure.
Size: 37 x 26 mm.
Color: Multicolor.
Face value: 1 ₽; 1 ₽.
Quantity: 2,000,000; 2,000,000.