A repulse booster was a part used in podracers. In 32 BBY, the boosters could be used as trade parts on Tatooine.
Tomo's mother gave Qui-Gon Jinn a repulse booster after he rescued her son from being held captive by Neg. Qui-Gon was then able to trade the repulse booster for a servo control system, which he needed to fix Anakin Skywalker's podracer.
Qui-Gon could also obtain the repulse booster by killing Tomo's mother and stealing it from her.
Tomo's mother gave Qui-Gon Jinn a repulse booster after he rescued her son from being held captive by Neg. Qui-Gon was then able to trade the repulse booster for a servo control system, which he needed to fix Anakin Skywalker's podracer.
Qui-Gon could also obtain the repulse booster by killing Tomo's mother and stealing it from her.