The Auburn FI21500 Spark Plug is a reliable ignition component designed to provide consistent spark generation in compatible HVAC and heating equipment. It works by creating a high-voltage electrical spark that ignites the fuel-air mixture, supporting dependable burner startup and operation. This spark plug is commonly used in gas-fired heating systems, industrial burners, and related... https://www.partshnc.com/fi21500-auburn-spark-plug