Number 6 of the k.u.k. Feldbahn (Imperial and Royal Field Railway) was one of five prototypes from different manufacturers which were tested at the beginning of the 20th century. It was built by MÁVAG of Budapest in 1902 and was the only one of the five that had an additional tender. The first of four driving axles was a Klien-Lindner axle that could be adjusted radially. The second and third axles were special in that they had outside wheel flanges, which caused problems when running over switches. In the end, this locomotive type was not produced in series and the prototype came to the Beszterce forest railway in 1918. 