They are slightly larger than the B3, the specifications are 25.3 m long over buffers, 42 tonnes in weight and seating up to 68 passengers.
The BF13 and BF14 are versions of the B5 with cabins for families with small children and people with physical disabilities.
The coaches were upgraded around 2010 and are now used in long-distance trains on following lines: These carriages are the longest ones operated by NSB.
Most trains with Class 7 carriages have one car with a playroom for families with children (BC7).
All Class 7 cars underwent extensive refurbishment in the period 2008–2011, including improved facilities for disabled passengers, power outlets at all seats, WiFi and free access to Internet.
[2][3] A usual Class 7 day train consists of 6 or 7 coaches: A usual Class 7 night train consists of 5 to 7 coaches: The WLAB2 is the newest, and since the retirement of the old WLAB carriages, the only type of sleeping carriage which is used on night trains on the Bergen, Dovre Sørland and Nordland Lines.