The G4 KnockLink from Link Engine Management is an LED warning light which provides a visual indications of when engine knock (pre-ignition) is detected so that action can be taken to prevent damage to the engine. The G4 KnockLink is easy to use, simply wire it in to a knock sensor. It is self calibrating and automatically profiles the engine RPM and load. Provides a visual warning when engine knock (pre-ignition) is detectedCan help prevent engine damageEasy to install with no set up requiredFlashes red when knock is detectedG4 KnockLink is supplies with a bracket to attach the LED warning light to the dashboard or roll cage where it can easily be seen by the driver.Requires a knock sensor for operation (not included).