Big Gun 40-R01 - 99-04 Honda TRX 400EX Rev Box

Big Gun 40-R01 - 99-04 Honda TRX 400EX Rev Box

If you are looking to swap out your stock CDI box, the Big Gun Over Rev Box is an affordable alternative to highly-priced OEM replacement boxes. It increases the overall RPM limit over the stock box and advances the timing curve.