First Day of Issue = December 28, 1936
Size: 23.00 mm x 28.00 mm
Quantity printed = 30,000
Perforated 10.00 x 11.50
Print method: Lithography

From www.latvianstamps.com

The "Latvian White Cross Society" had devoted it activities against alcoholism. It had applied to the Latvian Postal Administration for the issue of two sets of each 10 denominations with surcharges for the benefit of the society. This request was obviously refused, and instead on December 28th, 1936 a set of four denominations without a surcharge was issued.

Catalog numbers
Scott B93
Michel LV 243