This replacement part is a spark plug. This part is found in engines and assists in helping the engine start and run smoothly. The spark plug emits a spark of electricity, igniting fuel to create the combustion needed to start many machines and appliances. A new spark plug might be needed if the machine is unable to start or is struggling to start. Be sure the engine is completely powered off before attempting to replace this part. This is a genuine OEM replacement part manufactured by Champion Spark Plugs. This part is sold individually.