Big Gun Over Rev Box Honda CRF / XR 50cc-230cc The Big Gun Over Rev Box serves as a dynamic upgrade over standard CDI units, tailored for those seeking both performance and value. It easily integrates as a plug-in component, enhancing the engine's RPM ceiling while incorporating a refined timing curve. This adjustment not only boosts throttle responsiveness but also elevates top-end power delivery, marking a significant improvement in overall vehicle performance. Features: Increases overall RPM limit Advanced timing curve Easy direct plug in replacement to stock CDI box