The Armtech Rev Limiters provide effective protection against over revving of performance engines. They are precisely controlled using microprocessor technology and with their rugged design provide high reliability as well as ease of use. Suitable for use on any engine with a single or twin coil set up and contact breaker or electronic ignition. Includes a flat bracket for mounting to a panel or bulkhead.To determine the type of rev limiter required please check the ignition layout. Cars with a plug lead for each cylinder and a coil lead will need the single coil version, if there are coil packs you will need the twin coil version ( two or four leads for a four cylinder with no coil lead ) Cars with coils on the plug are unable to use this rev limiter ( no plug leads just small wires to the plug )