This is MSD sport compact ignition system that is dedicated to smaller displacement engines and well manufactured using high technology engineering process to create optimal performance. This product features a built-in Soft Touch Rev Control that drops the spark to individual cylinders then fires them on the next cycle to prevent fuel from loading up, producing an accurate and smooth rev limit. Suitable for 4, 6 & 8-cylinders engine, this product is able to create 105-115 mili-joules maximum energy output that is spectacular. It is also supported with rev limiter to create ultimate ignition performance for high revving smaller displacement engines. Here is the installation instruction of MSD ignition system that consists of coil harness, coil trigger wires, coil, tachometer, shift light, rpm activated switch, distich driver, etc.