Reverse The central part features a three-line inscription: 50 PENNIÄ 1908. Oak branch wreaths are placed along the left and right edges of the coin, not touching at the top. The branches are tied at the base with a ribbon forming a double bow. The rim is decorated with raised denticles.
Obverse The center of the obverse is occupied by the coat of arms of the Grand Duchy of Finland — a double-headed eagle bearing the titular arms of the Prince of Finland on its chest. Both eagle heads are crowned, and a larger third crown is placed between them, all three connected by a ribbon. The Finnish princely arms are a heraldic shield depicting a lion holding a sword in its right forepaw and a sabre in its left. A princely crown is above the shield. The shield is surrounded by the chain of the Order of St. Andrew the Apostle. In the eagle's left talon is an orb, in its right a scepter. Below the right talon is the initial 'L', indicating mintmaster Johan Konrad Liro (Helsingfors Mint). The rim is decorated with denticles pointing inward.