The HF6 (high-floor vehicle with six axles) is gradually replacing the common B80 vehicles in Cologne and the Rhine-Ruhr region. In Cologne, a total of 26 high-floor vehicles have been ordered and deliveries are to be completed in 2023. The vehicle was developed by Bombardier Transportation, now Alstom.

The six-axle vehicles have a length of 28m and a width of 2.65m and are equipped with a driver's cab. The livery is based on the predecessor vehicles. The white base colour and the red painted heads are very distinctive and well-known in the region.
The basic layout of the vehicles is essentially the same as the B80 vehicles.
The multi-purpose areas have been optimised and offer plenty of space for wheelchairs, walkers and prams. The interior is bright and spacious. The wide passage in between the cars, the high-contrast colour scheme and the tactile handrails support accessibility and orientation in the vehicle. Innovative passenger seats offer exceptional ground clearance and the retractable seat surfaces facilitate cleaning.

The vehicle with 62 seats can carry a total of 182 passengers. In addition, the HF6 vehicles have air conditioning and air suspension to further enhance comfort for passengers and crew.