The FXA-08GB(Bst) Core Booster "0088" is a variant of the FXA-08GB G-Core that initially appears in the Model Graphix Gundam WARS III: Gundam Sentinel (aka Sentinel Variations).
Technology & Combat Characteristics
Despite its high performance as an aerospace fighter, the small fuselage of the FXA-08GB G-Core gives it very limited armament and propellant space. To address these problems, the booster units used by the MSA-0011(Ext) Ex-S Gundam can be connected to the G-Core to form a Core Booster similar to the type introduced in the One Year War.
The standard version of the Core Booster can be used both within and outside the atmosphere. The utility space in the front half of the booster unit, which normally holds propellant tanks, is instead used for an adapter unit that includes landing skids and downward-pointing vertical wings. The main wings attached to the sides of the booster unit have a total of six hardpoints for missiles and optional equipment, and beam weapons can be installed on the movable frame mounts on top of the booster. The main wings can be removed to create a version exclusively for space use.