Director Pekka Parikka insisted on having a red star painted on the tanks, although there was no insignia on the Russian tanks during the Winter War, just an identification number painted on the turret.
The tanks used are original Soviet T-26, captured by the Finns during the Winter War or Continuation War (1941-44) and then serving as a backbone of the Finnish tank forces. Several are in driving conditions in the Finnish museum.
The anti-tank gun used by the Finns in the first assault is a Swedish Bofors "37 PstK/36" (37 mm, model 1936) bought from Sweden in the late 1930's. At the time of the Winter War the PSTK/36 (finnish designation) could penetrate the Armour of all Russian tanks. The exception being a heavy tank-model that was still in a prototype-stage and not widely used in the conflict.
Director Pekka Parikka wasn't actually planning to make an extended TV version back in the late eighties. He received financial help from Finnish Broadcasting Company, and they wanted him to make a miniseries for Finnish TV. It has an hour of additional footage compared to the original theatrical version.