This is an APC NetShelter rack-mount Automatic Transfer Switch (ATS), a 1U device that sits between two independent power sources (e.g. two separate UPS units, or a UPS and utility mains) and automatically switches a connected server or network device to whichever source is live, without manual intervention or downtime. This unit is rated 10A at 230V, takes a C14 power input and provides 12 C13 outlets for connected equipment, running on 50/60Hz mains. It's a redundancy component for data centres and server rooms with dual-corded critical equipment, letting single-power-supply devices still benefit from a dual-feed setup, and is not a UPS or battery itself.