Most Aviation EGT probes are type-K thermocouples (because the temperature range of type-J thermocouples is not has high as is required for EGT). All MGL Avionics EGTprobes are TYPE-K.

Note that the polarity of Type-K Thermocouples is not intuitive, as Red is Negative:

YELLOW = POSITIVE
RED = NEGATIVE

Read more about thermocouples here:
http://en.wikipedia.org/wiki/Thermocouple