Otherwise, the usual equipment for production motor cycles is what is comprised in a coil set: a battery (purists call it an accumulator) to supply electricity, a coil to transform that low-voltage supply to a much higher electrical pressure, with the assistance of a contact breaker which triggers it to provide a very high voltage pulse which is then led, either directly or through a distributor, to the appropriate spark plug where the pulse comes across the gap between the electrodes, igniting the charge in the process.