The Swift Shift from Micro Dynamics combines a shift light with a rev limiter in one compact unit.The Swift Shift also has capability for full throttle gear changes and a rapid start (launch control) option when used with a separately available switch.The rev limits for both the shift light and rev limiter are user settable with a 1/2 engine speed set up.Compatible with all negative earth contact breaker, optical breaker, transistorised and ECU ignition systems.The swift shift is supplied in a rugged reusable hard plastic case.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 )