MakerBot Smart Extruder thermocouple type

I've managed to destroy the thermocouple on my Smart Extruder (long, heavy-handed story). I need to replace it but I'm not sure what thermocouple type I need (e.g. E, J, K, etc.). If I use the wrong type in then I will get an incorrect temperature readback.

Does anyone know what type of thermocouple is used in the Smart Extruder? I've asked MakerBot tech support but they are not forthcoming with the thermocouple type (presumably because they want me to buy a new Extruder from them, not a $10 thermocouple elsewhere).

Help and advice appreciated - thanks! :)