The system serves five regions of southern Finland which in total account for approximately half of the entire population of the country.

At a total travel time of 1 hour and 15 minutes, it is the Main Line's fastest commuter service, calling only at eight stations.

Although the two legs share a common letter designation, the timetables remained nonsymmetrical and only three weekday departures run directly through the entire route, with services otherwise terminating at Kouvola.

The service has three different termini in the north; most trains terminate at Riihimäki but, departures extend to Tampere Central every two hours.

The Helsinki-Tampere service is the longest on the entire VR commuter rail network, spanning 206 km and taking 2 hours and 15 minutes to complete.

Certain peak and fringe hours departures continue up to Kouvola, mostly on weekdays, supplementing the O train on the Lahti-Kouvola section of the Saint Petersburg Line.

The prices are determined separately for each combination of stations – alphabetical zones have been discontinued on VR commuter rail as the network has grown massively over the years.

[4] All tickets for any Finnish passenger trains must be purchased in advance, with the exception of the Tampere region where platform validators are used.

Despite that, tickets issued by Nysse are valid on all commuter and long-distance services between Nokia and Lempäälä, as well as on regional trains up until the town of Orivesi.