The temperature probe supplied by Eagletree is a thermister on a wire loop. Eagletree says to loop it around the cylinder at the base of the cylinder.
I have installed the system and the speed and altitude readings seem to be OK. The temperature probe reads 198 with the engine cold. I hope that is just the minimum.
I intend to take it out and try it today.
The transmitter seems to interfere with the control radio. It may take some work to get it working OK.