This is a  simple guide to understanding how to properly identify your spa control system circuit board, at least enough to properly identify either the circuit board part number or in the event that the sticker has become unattached to the circuit board, you can still identify it by the primary chipset part number.  If your circuit board has the sticker still attached to the board, you should be able to easily identify the Balboa part number on it.  It will be the first set of numbers,