[2] In the late 1980s the Spanish firm Esperanza y Cia, which later became part of Instalaza SA,[citation needed] developed a 120mm caliber mortar bomb which contained 21 dual anti-armor/fragmentation[3] submunitions, each of which weighs 275 grams and is 37 millimeters in diameter.

What made the 120mm MAT-120s submunition unique is the electrical impact fusing system which for all practical purposes totally eliminated the risk of unexploded duds from subsequently detonating.

In addition there is no electrical energy stored in the MAT-120 round during storage, transport and even at the time it is fired from the mortar tube, thus greatly reducing any risk of premature detonation.

[4][5] The action of firing the round starts a timer which triggers opening the projectile, scattering the submunitions, which land in a random pattern between fifty and sixty meters in diameter.

[8] (In its 2011 Convention on Cluster Munition submission, the Spanish government reported that the number retained had fallen to 366 MAT-120 and 331 ESPIN)[9] The Spanish Government has refused all export licence applications for cluster munitions, including this weapon, from 11 June 2008 onwards[8] although as of April 2011 it is still listed on the product page of Instalaza's website,[3] In April 2011, there were news media reports of Libyan forces loyal to Gaddafi using MAT-120 mortar rounds against the besieged city of Misrata,[10] although the Secretary of State of the US,[11] Hillary Clinton said she was "not aware" of the specific use of cluster or other indiscriminate weapons in Misurata.