The coil pack has two coils in it along with transistors (ignitor) to fire the coils. The front two cylinders share the same coil and the two rear cylinders share the same coil, so two plugs fire at the same time. (wasted spark) Get a coil and plug wires from a scrap yard. You don't want an aftermarket coil. If you buy plug wires or spark plugs, get NGK.