The MF of the Danish State Railways are diesel multiple units which can be recognized by their air-tight rubber noses. The noses are inflated with air. While coupling to another unit, the air is shortly being deflated and inflated again to match the shape of the other unit. Inside the noses, there is a cab that can be folded away to make space for the passenger gangway.
Technically, each set consists of three car bodies which are running on four bogies, the inner two of which are Jacobs bogies. From a total of four Deutz diesel engines, each one is connected to one axle of one bogie via a mechanical gearbox. Each engine delivers 400 hp and starting in 2005, these were changed against new Deutz engines with 450 hp each.
The approved top speed is 180 km/h and in 1991, one train set the new Danish rail speed record with 204.6 km/h. These trains are also operating into Germany and are reaching Hamburg. Starting in 2018, they were refurbished. The Spanish class 594 is closely related to the MF, but only consists of two cars. An optically similar EMU is called X31K by the SJ and operates between Sweden and Denmark.