My foot says P2 and it is the one that came with the machine...if you can ask the previous owner...if that is possible...you probably have the wrong foot...
I just bought the new FMQ foot QA...and the Bobbin Holder for FMQ..with the blue dot..but haven't used them yet..apparently they are supposed to be very helpful...the foot has a spring that allows you to adjust for differnet thicknesses...and the bobbin holder has appropriate tension setting for FMQ..just save having to adjust tension on the regular (red dot) bobbin holder..