The SB-920 laser cannon was produced by Borstel Galactic Defense. These cannons were made solely for use on Imperial starships and the Death Star. A single gunner operated the weapon from within a sealed, pressurized compartment. Firing occurred through magnetic Force field protected openings.
In Star Wars: Complete Cross-Sections, the Death Star's laser cannons were initially labeled as Sienar Fleet Systems L-s 4.9 laser cannons; however, later publications attributed them to Borstel as SB-920 cannons.