Thanks for the reply! Yes, it's Fios.

I see the router you mentioned on Amazon for $40.

https://www.amazon.com/FIOS-Verizon-Gateway-Quantum-G1100/dp/B01ETSPPEO

They use WiFi for general surfing on a laptop and light smartphone stuff, but they also use if for watching movies stored on a MacBook and streaming it to a television with Chromecast. Will that router suffice? Also, they get pretty good WiFi connectivity in the basement and they would want that to stay the same also. Thanks again.

ETA: I see that the router I linked to on Amazon is used and I can get one on eBay for the same price seller refurbished. Should I go with eBay?