81-717/714 is a metro car designed for rapid transit systems of the Soviet Union, as well as its satellite states, in the mid-1970s. A number of Eastern European countries use modified variants of these metro cars, such as the various models used in Poland: 81-717.3, 81-714.3, 81-572, 81-573, 81-572.1, 81-573.1, 81-572.2, and 81-573.2. The Prague Metro in the Czech Republic still has these units, but modernized into variant 81-71M in service. Most variants of the 81-71 family are visually almost identical to the 81-717 and 81-714, except for 81-572.2, which has a cabin that resembles the 81-540.2 (another Russian metro car, an improved version of the 81-717 that was first produced in 2006).
These metro trains are still in service in Moscow, Saint Petersburg, Sofia, Warsaw, Budapest, Yerevan and Tbilisi. The Czech modernised version (81-71M) is commonly used in Prague, transporting passengers on two lines out of 3.