The MO-120 RT (factory designator) or MO-120-RT is a French heavy mortar. The RT in the designator stands for rayé, tracté, which means rifled, towed. The MO-120-RT is currently used by the French Army (where it is known as RT F1 or Mortier de 120mm Rayé Tracté Modèle F1—"120 mm rifled towed mortar, model F1"), and has also been exported to more than 24 foreign countries or in some cases, produced under licence. It is issued to artillery units, where it complements artillery guns and systems; although infantry units operate it in some countries.