A repulse booster functioned as a component utilized within podracers. Back in 32 BBY, these boosters held value as tradable components specifically on Tatooine.
Following Qui-Gon Jinn's rescue of her son from imprisonment by Neg, Tomo's mother gifted him with a repulse booster. Subsequently, Qui-Gon leveraged the repulse booster in exchange for a servo control system, an essential item for repairing Anakin Skywalker's podracer.
Alternatively, Qui-Gon had the option to procure the repulse booster through lethal means, by eliminating Tomo's mother and appropriating the item.