2003-2004 Predator 500 Rev Box (BIG40-R10)The Big Gun Rev Box for the Polaris Predator 500 is a high performance electronic upgrade designed to unlock the full potential of your engine. As an affordable alternative to expensive OEM replacement CDI boxes, this unit is engineered to provide more aggressive power delivery. By increasing the overall RPM limit over the factory settings and advancing the timing curve, the Big Gun Rev Box allows your engine to pull harder for longer, providing a