MSD Ignition RPM Controls Three Step Module Selector Features: Allows User To Switch Between 3 RPM/Timing Modules Set Different RPM Limit For Burnout/Launch/Overrev Can Be Used w/Timing Controls For Retard Changes Must Be Used w/MSD Soft Touch Rev Limiter Must Be Used w/MSD Timing Control No RPM Or Retard Modules Are Supplied Height: 3.00 Width: 6.00 Length: 6.00 Weight: 0.40 lbs Vehicle Type: 2715