The GSI-21D, a disruptor pistol, was produced by Galactic Solutions Industries. During the New Sith Wars, this weapon was favored by officers and experienced combatants within the Brotherhood of Darkness's Sith military. Due to its considerable destructive capacity, possession of the GSI-21D was outlawed across most sectors under the jurisdiction of the Galactic Republic. It demonstrated effectiveness in the vaporization of organic tissue, droid plating, and armor.
The GSI-21D represented a formidable pistol, standing out as one of the most potent disruptors accessible during the New Sith Wars. It earned recognition as the premier disruptor pistol crafted by Galactic Solutions Industries in the years leading up to the Battle of Ruusan. Each power pack provided sufficient energy for a dozen shots before requiring replacement. The pistol's maximum effective range extended slightly beyond twenty meters, although its optimal performance was achieved at distances below twenty meters.
Within its optimal range, the GSI-21D could effortlessly obliterate flesh, bone, droid plating, and armor with consistent efficiency. Its lethal capabilities resulted in its prohibition within the majority of sectors of the galaxy governed by the Galactic Republic.
Galactic Solutions Industries conceived and manufactured the GSI-21D disruptor pistol sometime before the Battle of Phaseera. This pistol was commonly issued to officers and seasoned soldiers who had demonstrated their martial prowess within the Brotherhood of Darkness's Sith forces. Dessel, a sergeant belonging to the Gloom Walkers division of the Brotherhood of Darkness, wielded a GSI-21D during his participation in the Battle of Phaseera. Following Dessel's arrest by the Sith army for assaulting his commanding officer, Lieutenant Ulabore, his GSI-21D was confiscated prior to his incarceration in prison as he awaited court-martial.
The GSI-21D made its debut appearance in the novel Darth Bane: Path of Destruction, authored by Drew Karpyshyn and published on September 26, 2006. In December 2008, an entry dedicated to the pistol was included in The Complete Star Wars Encyclopedia.