Hi Andy thanks for the reply.

The parts book for the MC21 lists 3 different PGM units for the various levels (different end numbers 830, 831 and 901).

I was just wondering how you could identify which one you have because all the ones I have seen do not have the part number on them. They all do have an inked code on them which has a manufacturer code and then a date/batch code after it in smaller letters.

Cheers