Metre–tonne–second system of units
The metre–tonne–second (MTS) system of units was invented in France (hence the derived unit names sthène and pièze) where it became the legal system between 1919 and 1961. It was adopted by the Soviet Union in 1933 and abolished there in 1955.
Source: Wikipedia — Metre–tonne–second system of units (CC BY-SA 4.0)