The following topside control panels are compatible with the above circuit board: 51705 & 54116 Balboa circuit boards are marked with a �Chip Number� that is located on a white label placed on the logic chip near the center of the board. It is imperative that this number is supplied to Aqua-Man Tech Support staff for proper circuit board match. Just because boards may look similar the programming may not allow it to work properly in all applications.