Which OEM temperature sensor for Sterling regulator?

[Cantata]

Going to fit a s/hand Sterling smart regulator, it didn't come with a temperature sensor. Can get one from Sterling, but it's a tad pricey especially after adding on the postage.
I guess this is a standard part from somewhere else. Anyone happen to know where I can get one, please?

 

[pvb]

As there seems to be no way of knowing the specification of the Sterling sensor, I guess you'll have to buy theirs.