Due to their boxy shape, and angled cab ends, the members of the class have been nicknamed "Tetrapaks".

Opened in 1908, the line was completely refurbished in the late 1960s, and is now operated by the Železničná spoločnosť Slovensko (English: Railway Corporation of Slovakia) (ZSSK).

The fifteen members of the ZSSK Class 425.95 were gradually introduced from 2000 to replace them, and now operate all TEŽ services.

The middle section, with a carbody made of steel, is fitted with electrical equipment and traction motors driving a twin axle bogie.

Each of the lightweight outer sections, made of aluminium, has a passenger compartment, a driver's workstation, and an unpowered twin axle bogie.

In the boarding area inside the doors, there are outboard folding seats, 10 holders for skis or bicycles, and handles for standing passengers.

Interior lighting is provided by fluorescent lamps, and the passenger compartments also have visual information systems, with multilingual acoustic stop announcements.

The testing process revealed certain incompatibilities between modern vehicles and the TEŽ's then outdated track and power systems.

The latter therefore required some conversion work, including reprofiling of the lines in some sections, reconstruction of the platforms across the network, and also adjustments to the power system to enable it to benefit from the new vehicles' regenerative brakes.