Balboa GS 501Z Printed circuit board.
Looks different to original PCB from the SCS501 controllers but still fits and has the same functions.
PCB can have the following set up functions:
1x Circ Pump, 1x 1 Speed Pump, 1x Blower, Ozone, Light.
1x 2 Speed Pump, Blower, Light, Ozone.