The Intermatic PB913N66 is a generic, mechanical, 24-hour panel-mount timer mechanism (120V) designed for controlling pumps and other loads in pool and spa applications.
It is not a proprietary part specific to one or two spa manufacturers. Instead, it is used as a component within many different brands' overall control systems.
The timer is primarily used in external time clock control boxes (often labeled Intermatic PF or RC series) rather than in a spa's internal topside control panel, like the Balboa parts.
Therefore, a "laundry list" of manufacturers using this timer isn't as straightforward as a single topside panel. Any spa manufacturer or system builder that uses an external electrical control box requiring a 120V mechanical timer mechanism could potentially use this part.
Manufacturers known to integrate this style of generic Intermatic timer into some of their systems or use it as a compatible replacement include:
Garden Leisure
Jacuzzi Whirlpool Bath (in some electrical components)
United Spa Controls
Nu-Wave Spa Controls
Acura Spa Systems
The part is widely available from third-party retailers, who market it as compatible with systems from various brands like Pentair, Hayward, Jandy, and Sta-Rite when used in a universal or multi-brand control system enclosure.