What’s compatible with Orbi RBR850

[SLONGNION]

I have an Orbi RBR850 Router with one Satellite. I need to extend this, but cannot purchase another Satellite anywhere. Not offered unless used. What products are compatible with the RBR850? It’s almost impossible to find much information in this model. Thanks.

[FURRYe38]

RBS750, RBS850, EX7500, 7700, 8000 and EA80 work with Orbi AX systems.