Master Spa control system, spa pack MS8500 X300790.

Includes the 5.5kW heater.  Control panel sold separately if needed. See MASX310120 with overlay MASX509009.

If you were referred to this part, it is the right control box with circuit board for your Master Spa.

Special order item with lead time of about 7-10 days.

X300790 MASX300790

contact us for current availability