This is an APC Rack Automatic Transfer Switch (ATS), a device that sits between a piece of rack equipment and two independent power feeds (e.g. two separate UPS units or utility circuits), automatically switching to the backup source if the primary feed fails or drops out of tolerance — protecting single-corded equipment from a single point of power failure. It's rated 230V/32A, with two IEC 309 (industrial "commando" style) inputs to accept two separate power feeds, and outputs via 16x C13 and 2x C19 sockets, enough to power a meaningful bank of servers, switches or other rack gear from redundant sources. This is a data-centre/server-room reliability product rather than a UPS itself — it doesn't store power, it just ensures continuity between two already-protected feeds.