This Type J thermocouple is designed for use with our Westberg Cylinder Head Temperature Gauge, Part No. WBT-2C1 (sold separately). Self-powered thermocouples generate a small amount of voltage based on the difference in temperature from the hot (probe) end and the cold (cable) end.
The 14mm ID ring fits most common spark plug threads, including FF1600. The 12 inch lead can be extended by adding a Thermocouple Extension Cable (Part No. 1086, sold separately). Sold individually.