The Frecciarossa 1000 is a high speed train of the Italian State Railway with an operational top speed of 350 km/h. The name stands for “Red Arrow”, while the manufacturer calls it ETR 1000 and its official designation of Trenitalia is ETR 400. While it was in the design stage, it was also known as “V300 Zefiro”.

Each set consists of eight four-axle cars and is related to the Zefiro trains in use in China. They can be operated under 25 kV AC, 15 kV AC and 1,500 V DC, while the top speed of 350 km/h can only be reached under 25 kV. In trials, one even reached a speed of 393.8 km/h.

Design and manufacturing was jointly carried out by AnsaldoBreda and Bombardier. After AnsaldoBreda was taken over by Hitachi and Bombardier's rail division was taken over by Alstom, the design is now partially owned by Alstom, which had unsuccessfully taken part in the bidding process. After the initial order for 50 sets, Trenitalia ordered 30 more in 2023 with an option for ten more.