The metro system of Milano consists of four lines with a total length of 100 km. The electric system is mixed, with trains of some lines taking their electricity from additional rails, some from overhead catenary wires. This picture is from the M1 line, from the station of Cadorna FN. This line was opened in 1964 with its latst addition in 2005. This line 1, electrified at 750 V DC, uses a fourth rail system, although the same line also supports overhead lines in some stretches and depots; this allows Line 2 and 3 trains to use Line 1 tracks to reach a depot. This is a so called Ansaldobreda Meneghino train. They were built since 2009. They have multiple electric systems, which allows them to be used on Milano's metro lines 1, 2 and 3, either 750V DC or 1500 V DC from either a third rail or from a catenary wire. Milano's metro lines are colour coded and the green colour signals that this train serves on line M2.
Picture from the station Cadorna FN 7.7.2019 by Ilkka Siissalo.

Inside view of an Ansaldobreda Meneghino metro train.
Picture from the station Cadorna FN 7.7.2019 by Ilkka Siissalo.

A newer line M2 train of Milano. This train model is called Leonardo. They were ordered from Ansaldobreda, but after Ansaldobreda went bankrupt and Hitachi bought the factories, they were actually delivered from Hitachi. The last ones entered service in the summer of 2018. These new trains are 107 metres long and can be walked right through. Top speed is 90 km/h.
Picture from Milano Centrale FS 7.7.2019 by Ilkka Siissalo.

Side view of the new Hitachi Leonardo train of line M2.
Picture from Milano Centrale FS 7.7.2019 by Ilkka Siissalo.

The metro line M5 of Milano is operated by totally driverless metro trains which are from the factory that earlier was of Ansaldobreda, but now after the bankruptcy of Ansaldobreda is owned by the Japanese Hitachi Rail. They are four coaches long and totally automated.
Picture from the metro station Milano Domodossola 7.7.2019 by Ilkka Siissalo.

Another one of the totally automated line M5 trains. They are notably difficult to photograph because they run totally insulated from outside standing people on the platforms, the tunnels have very little light and the trains run fast. Here the train is just leaving the station.
Picture from the metro station Milano Portello 7.7.2019 by Ilkka Siissalo.