This 123 Ignition Distributor replaces most 4 cylinder Lucas distributors, be it 6 or 12 volt. This product can be wired to positive or negative earth vehicles and can replace both clockwise and anti-clockwise distributors (View from driven end). It offers 16 different advance-curves that can be selected via a little switch which enables you to fine tune your engine. It also offers automatic dwell, spark balancing, automatic power cut off one second after engine stops. Note that there are dedicated 123 Ignition distributors for Mini, Sprite, Midget, MGA & MGB. If Triumph owners need a connection for a mechanical rev counter, this distributor does not offer this facility