The 6AL-2 is the new generation of ignition controls from MSD featuring a new housing, digital controls and more power in a sleek package. Inside every 6AL-2 is an advanced micro-controller that manages the timing and rpm of the ignition as well as maintaining a spark output of 535-volts. In order to ensure complete combustion, the multiple sparks burn inside the cylinder for 20° of crankshaft rotation. Two other benefits are the rev-limiting controls: one for high-end over rev and the other can be set to activate off a clutch or trans-brake to set a launch limit. Rev limiters are controlled via rotary dials providing easy adjustments at any time. Ignition boxes are sold per each and include wiring, vibration mounts and complete instructions. Compatible with 4-cylinder, 6-cylinder and 8-cylinder engines.