One of an engines worst enemies is detonation. It can occur at any time and if left uncontrolled, severe engine damage may result. Sometimes however, the pinging noise may be hard to hear or recognize due to well insulated interiors, engine compartments or excessive road noise. The MSD Engine Knock Alert listens to what's going on in the engine for you. When detonation occurs, it relays this information to you in two forms; a warning light and an audible beep. An extremely sensitive Knock Sensor is used to ''listen'' to the engine. This sensor is screwed into one of the engine block's drains or access holes (an adapter mount is also supplied). Once in place, the sensor relays excessive detonation noise to the Knock Alert. Since all engines make noise, some more than others, MSD added a sensitivity adjustment to the Alert. This adjustment allows you to ''tune'' the Alert to match your engine's characteristics. The Knock Alert is easy to install and features matching Weathertight connectors for firm connections. It will work on 4, 6 and 8-cylinder engines with 12 volt electrical systems and comes complete with the sensor, adapter and controller.