The Sacros K-11, alternatively referred to as "The Disintegrator", was a type of blaster pistol that saw use circa 0 ABY.
On Panna Prime, Boba Fett carried one of these weapons. As a ploy to deceive Chewbacca into believing he was an ally, he tried to shoot at a pursuing Stormtrooper speeder. Chewbacca, annoyed by what he perceived as Fett's ineptitude with the weapon, grabbed the blaster and obliterated the speeder.
The "Holiday Special Boba Fett Character Key" from Acme Archives was the first time this weapon was named. The Boba Fett "Black Series" SDCC limited edition action figure included a description breaking down Fett's weaponry and labeled his Empire Strikes Back blaster as a "Sacros K-11 Disintegrator Pistol."