I upgraded an old one to a CyberPower from Costco... I read through this:
https://www.cyberpowersystems.com/blog/buying-guides/choosing-a-ups/ and decided I needed a True Sine Wave one to connect my Router, a PC and a monitor. Hopefully if I shut down the PC and monitor in a few minutes, I have WiFi and landline service for a few hours. (Longest power outage I've had is 2 hours.)