This small Finnish coin represents the 4th denomination coin of the First Markka (Series 1939). The observe depicts the Finnish Coat of Arms, with a split mint date (1939). The reverse features the coin's 25 Penniä value wreathed by a pair of wheat spikes. Notably this coin was in circulation during the Winter War (1939-1940), fought between independent Finland and the Soviet Union.
The coin is a reeded-edged design made of a Copper-Nickel alloy and weighs 1.27 g. Its dimensions are 16 mm (0.63 in) wide and 1 mm (0.039) in thick. Making it smaller in size than a US Penny (19.05/0.75 in), in that respect.