This compression fitting provides a solution for obtaining a coolant temperature reading without having to cut into the radiator hose or place a thermal probe in the radiator fins. Suitable for use with the Davies Craig digital thermatic EWP / fan switch or the mechanical thermal fan switch controller.Removes the need to cut the top radiator hoseFits a 1/4" NPT port in the cylinder head, thermostat housing, radiator or engine blockIncludes 5mm and 6mm compression olives for different diameter probes.This fitting is designed to screw directly in to a water port which could be located in the cylinder head, radiator, thermostat housing or cylinder block. The thread is 1/4" NPT but adaptors are available to different threads is required.