 The Zastava M90 is the modified version of Zastava M80, itself a version of the Zastava M70 (chambered in the Western 5.56×45mm NATO round), also comes with a flash eliminator and different magazine design, which means that like its predecessor, the M90 is a modified Soviet AKM.It is gas-operated, air-cooled and magazine-fed, shoulder fired weapon with selective fire capability, and like M70, can launch rifle grenades and has a rifle grenade sight added on the gas tube, instead of under barrel grenade launcher like on most other AK variants.It also incorporates the adjustable gas system from its M76, M77 and B1 cousins, with the third gas position being the gas cutoff for grenades.