The Dm6 and Dm7 were diesel multiple units built by Valmet in the 1950s and 1960s for Valtionrautatiet.

[1] They are known by their nickname lättähattu (Finnish for "flat cap", the first widespread youth culture movement in Finland).

[2] At the beginning of the 1950s it became clear that VR needed multiple units to compete with buses in short-distance traffic.

[3] After testing the Dm6:s and having noted that the new DMU:s worked well in Finnish conditions, VR ordered more units.

[4] In total, 197 Dm7 class multiple units were built with some modifications (a larger wheel size, for instance).