The Varon-T disruptor was a hand-held directed-energy weapon banned in the Federation due to its vicious nature: the disruptor literally tore the body apart at the molecular level from the inside out, resulting in a relatively slow and excruciating death by disentigration compared to most phasers and disruptors. Only five were ever produced; four of them were owned by Zibalian trader Kivas Fajo and he slept with one of them under his pillow. Fajo used a Varon-T disruptor to kill Varria when she and Data attempted to escape his ship. (TNG: "The Most Toys")
The props used for the Varon-T disruptors were a reuse of the Mariposan phaser-like pistols from TNG: "Up The Long Ladder" and they were later reused again as a Rutian Ansata terrorist pistol in TNG: "The High Ground", a pistol of the Ferengi Sovak in TNG: "Captain's Holiday", a pistol of the mercenary Kelsey in TNG: "Starship Mine", phaser pistol used by the mercenaries in TNG: "Gambit, Part I", "Gambit, Part II", a pistol of the Native American colonists of Dorvan V in TNG: "Journey's End", a Maquis pistol in TNG: "Preemptive Strike" and an alien weapon in VOY: "Fair Trade".
It is not clear if some of these weapons were intended to be Varon-T disruptors. Only in "Gambit, Part II" the reused prop was identified as a phaser. The type of the pistol was not identified in the other instances. TNG: "The Most Toys" was also the only episode in which this weapon was shown to produce the distinctive painful disintegration effect.