The Sm6 Allegro is a 200 km/h high-speed train that operates on 1524 mm gauge in Finland and 1520 gauge in Russia between Helsinki and St. Petersburg. The wheel sets have 1522 mm gauge and are certified for 220 km/h. Operated by Karelian Trains, a 50–50 joint venture between VR Group and Russian Railways RZD. The units have dual-voltage electrical equipment able to use both the Finnish 25 kV 50 Hz AC and the Russian 3 kV DC electrification.