Exceptionally large size, 23mm. Very cool.
In 1939, right on the eve of the Winter War, on October 20, an article was published in Helsingin Sanomat and Uudi Suomen, suggesting that Finns exchange their gold rings for iron rings so that Finland could acquire war equipment.
The collection was delayed so that it could not actually start until after the winter war on April 2, 1940. About 315,000 rings were collected and in addition 19,100 other gold objects[1]. The Ministry of Defense was able to collect a total of more than 1,750 kilograms of gold. With that amount of gold, up to 30 fighter planes could have been purchased. In return, the donors received cheap rings called iron rings, made of new silver, i.e. alpaca. Two types of rings were made, i.e. a smooth iron ring and the so-called an air defense ring with an Air Force emblem. 30,000 rings remained unexchanged during the war.