The MSD Ignition Series Circle Track controller features a built-In Start Retard, LED display which is easy to read and can be used on 4/6/8 cylinder engines. The controller has a universal plug-in system, three rotary dials and can be adjusted in 0/10/20 increments. The controller can also be set to "tach" mode. It is a highly efficient controller while at the same time very energy efficient.