Zetor was the first in the world to come up with a progressive and unique concept of using unified elements in the production of tractors, i.e. with the possibility of using identical parts for different models, thus greatly simplifying production and service. In 1960, the Zetor 3011 was launched on the market – the basic model of the revolutionary unified series – UŘ I. This was followed by other models of this series – Zetor 2011 and 4011, for which a new numerical designation of individual models was also introduced, taking into account various modifications.
Классификация тракторов серии UŘ I составлена по книгам "Encyklopedie českých traktorů", "Historie traktorů Zetor" и "Opravy traktorů Zetor".
UŘ - Unifikovaná řada (Unified range).
Цифровое обозначение моделей велось следующим образом:
WheelsAge.org '2005–pres.