This MSD switch requires no RPM modules. Its RPM activation points are programmed simply by scrolling through the LED display to RPM amounts (from 200 to 15,000 RPM in increments of 100).

The switch accepts an input RPM signal through a coil negative terminal (for stock ignitions), tach output of an ignition control, 5-volt tach signal, or ECU. The switch can be used with an input voltage of 9-18 volts, and it has two outputs (one normally open, one normally closed). You can even control a shot of nitrous on nearly any engine combination.