The PLX-4 Missile Launcher represented the newest iteration in a series of launchers conceived by Merr-Sonn Munitions, Inc., a lineage that began with the PLX-1.
Its adaptability made it a potent weapon for infantry personnel. It possessed the ability to launch both conventional rockets and missiles, alongside more sophisticated projectiles. The initial type was the Gravity Activated Mode, a technology inherited from earlier PLX launchers and functioning identically. The second type consisted of specialized "Savant" missiles, computer-guided projectiles engineered to simulate standard unguided missiles until a pre-determined moment, at which point they would activate their homing capabilities. This tactic often deceived targets into believing they had evaded the missile, only to be struck unexpectedly.
The PLX-4 could be fired either from a shoulder-mounted position or when mounted on tripods (though these were not manufactured by Merr-Sonn). It was equipped with a removable missile magazine capable of accommodating four rockets.
Following the Battle of Endor, the PLX-4 became commercially accessible. The Galactic Empire quickly embraced the PLX-4, deploying it extensively on planets such as Qat Chrystac.