CHT Thermocouple Probes 
Includes fire sleeve and ring terminal hardware. Two different mount styles are available:

Bayonet Mount
These twist and lock into a screw-in adapter. The probe is spring loaded to ensure contact with metal instead of air. Choose bayonet style if the engine model is equipped with threaded thermowell receptor and/or bayonet adapter in the cylinders.

Gasket Mount
These do not require a screw-in adapter. The 18mm gasket fits on many common spark plugs. Some engine designs, such as radial engines, the O-235 and O-200, may prevent the use of bayonet style or may not allow for the use of a bayonet adapter. Choose gasket style if the engine model is NOT equipped with threaded thermowell receptor and/or bayonet adapter in the cylinders. 

*A new installation of P/N 86251 requires P/N 28202 as well.

** Does not require bayonet adapter. Screws directly into the thermowell.

For more information on probes, go to Thermocouple Probes.