Batboard

I have a Motorola Service monitor with the numbers
R-2001A/U serial number
415 KFK 0006
Does anyone know what the "U" stands for I have taken a picture of the TAG but can not figure out how to post it here.
Thanks for anyone that knows, I've never seen a /U listed anywhere I've looked.
Thanks again.

Sold as used after trade-in.

ok Dave thank you very very much. This unit has a Bad J2 card I have a C unit with no power supply and the cards are all suspose to be good. will you please look at my other post about LVPS and let me know if anything is able to be swapped between the two units.
Boy we are sure lucky to have you here Dave and the awesome help you give us. I have units that I got from the Bay and have 2 working.
Thanks again Dave for your expert information.