Like its base unit, the RGM-89 Jegan, the RGM-96X Jesta can adapt to different needs through the use of dedicated option parts, resulting in multiple variants. An example of this is the Jesta Cannon, a heavy armed variant with enhanced firepower via the addition of a beam cannon, a quadruple multi-launcher, more hand grenades and an enhanced beam rifle. It also has added body armor, including an arm-mounted shield, but their placement is kept to a minimum after considering weight balance. When needed, the added armor can be purged instantly using explosive bolts. To handle the added weapons, the Jesta Cannon's fire control systems has been improved. Not only can the Jesta Cannon serve as a mid-range fire support unit, which is a function synonymous with mobile suits that have the word "Cannon" in their name, it can also fight at the frontlines without any issues due to its enhanced offensive capabilities.
There is one confirmed Jesta Cannon in the Ra Cailum's MS teams, and it is piloted by the Tri-Stars Team's Watts Stepney. The Ra Cailum also carried parts for converting 4 more Jestas into the Jesta Cannon.