The Tan Chong ignition coil is high voltage (low current) transformer that converts the vehicle’s 12 volt power supply to the 25-30,000 volts required to jump the gap of the spark plug, thus instigating combustion ignition coils should always be replaced in sets. All the coils on the vehicle have done the same work, therefore, if one has failed then the others will be on their way out – by replacing single unit, the risks of a further ignition fault are significantly increased. When fitting a replacement coil it is essential that high quality unit is used to avoid further premature failure. Tan Chong ignition coils are rigorously tested to ensure that they meet the OE specification and give installers confidence that they are fitting a quality product that will offer high levels of performance and an optimum lifetime. Packing - 1 box