This has been tested and taken from my own home network (Orbi 750 mesh system) so in full working order.
This was originally a Orbi RBR750 router, but has been modified to show up as a RBS750, so now accepts RBS750 firmware (Satellite). Setup is exactly the same when adding your existing Orbi mesh system, you go to the “Add Satellite” section on the web browser (or app), switch on the converted RBR750, wait for it to fully start up (2-3 mins and will flash various colours) and then hit the sync button on the back and “Add Satellite” in the software and wait for it to connect. I would advise placing fairly near your router (same room) for the initial connection, and then once it’s on your system, move to the required position and wait for it to connect. As with an original satellite you can connect via Ethernet too, should you wish to connect to a wired backhaul for a faster mesh connection. And because this has 4 Ethernet ports on the rear, this is actually an improvement on an original satellite, as you have more ports should you need them. The original satellites only have 2 Ethernet ports.
The unit has a few marks on it, but nothing that affects how it works.
Happy to answer any questions should you need it.
Comes from a smoke free home.
This is a very good Mesh system, and I’ve found them to be very reliable.