APC SUA2200 uninterruptible power supply.
Works fine but needs new batteries and I took the opportunity to downgrade to a smaller unit since this one is overkill for my needs.
Full specs here: https://www.se.com/be/en/product/SUA2200/apc-smartups-2200va-usb-serial-120v/
Wired for a 20A outlet but can be swapped to a standard 15A plug for a few dollars: https://www.amazon.com/dp/B000FKBZ7M
Rated at 1920VA/1920W on 20A supply, 1440VA/1440W on 15A supply.