The tech bulletin doesn't make it very clear what the "x" means, so here goes: "x" refers to the first digit of the 9 digit serial #. If the first digit is 1, the unit was made in Germany. If the first digit is 2, it is a U.S. made product....etc. The country of origin is not important, just the next 8 digits- that is the serial #. A part that is described as : (right facing arrow)x12345678 means that this part fits serial #12345678 and up, regardless of the country of origin. Sorry, my keyboard doesn't have a "right facing arrow" key. Hope this also helps.
