First Day of Issue = April 30, 1920
Size: 27.50 mm x 32.00 mm
Quantity printed = 1,017,387
Perforated 10.00 x 11.50

SATVERSMES SAPULCES PEEMIŅAI translates to IN MEMORY OF THE CONSTITUTIONAL ASSEMBLY

Catalog numbers
Scott 73
Michel LV 45A

For more information check out the links below
First Constitutional Assembly