These "under the sparkplug" CHT probes are popular choices for CHT temperature monitoring. Constructed using a two part system a copper lug and K-
Sizes to suit 10, 12, 14 and 18mm spark plugs.
Most automotive engines and Rotax two strokes use 14mm plugs, the Jabiru engines and Rotax 912/914 use 12mm plugs. Lycomings and Continentals use