The RFID inlays replace magnetic-stripe cards the train system now uses for tickets with a fixed number of journeys. Seasonal tickets already employ contactless RFID smart cards to speed up long passenger lines. The company is set to deliver 5 million inlays monthly, ramping up to about 30 million monthly by this summer. The Moscow Metro is one of the world's busiest metro trains. It carries 8.2 million passengers on a normal weekday.