This Rick's Hot Shot CDI Box will increase the rev limiter an additional 1000 RPM in forward and reverse. Modifications are specific to each model. CDI box enhancements may include one or more of the following: multiple spark, increased rpm redline or altered ignition advance curves. Advance curve allows ATV to rev at higher rpm and quicker rate. Also may be used to replace defective CDI box on stock machines. � Increases the rev limiter an additional 1000 RPM in forward and reverse Enhancements may include: multiple spark, increased rpm redline or altered ignition advance curves Advance curve allows ATV to rev at higher rpm and quicker rate May be used to replace defective CDI box on stock machines