A variation of the Gundam F91, it has a new backpack equipped with four Variable Speed Beam Rifles (also known as VSBRs) - two more than the original backpack. The four VSBRs are an improved version of the original and have auxiliary thrusters, boosting the mobile suit's thrust.
Also known as VSBRs, these weapons can fire either low-speed beams with high destructive power, or high-speed beams with high penetrating power, sufficient to destroy two MS with one shot or pierce a beam shield. The Gundam F91 Twin VSBR Type has four VSBRs mounted on its backpack, two more than the normal Gundam F91. When deployed, the two bottom units slide under the shoulders while the two top units remain positioned above the shoulders. Furthermore, the Gundam F91 Twin VSBR Type's VSBRs have added auxiliary thrusters, boosting the Gundam's thrust and possibly mobility.