These are the CHT probes. Pretty easy install. Mine had screw in barrels that have slots for a screw driver. Just screw them in the Heads and adjust the BNC's on the probe for the correct length then slip them up, compress the spring and then 1/4 turn to lock them in place.
Barrel screwed in the head
This is the probe.
Probe just before going in the barrel at the head.
