APC AP7721 Rack ATS Automatic Transfer Switch – 1U, 120V, Rack-Mountable. The APC AP7721 Rack ATS (Automatic Transfer Switch) is designed to provide reliable power distribution and seamless failover protection in critical server environments. This 1U rack-mounted unit ensures that your equipment stays powered, even in the event of a power failure, by automatically transferring power between two sources. Automatic Power Transfer : Ensures continuous power by automatically switching to an alternate power source if the primary one fails. 1U Rack-Mountable Design : Saves valuable rack space while providing a compact solution for server and network equipment. 120V Input Voltage : Compatible with standard 120V power systems for easy integration into your existing setup. High Reliability : Ideal for data centers, server rooms, and other critical infrastructure that require uptime and minimal downtime. Easy Setup : Designed for simple installation with rack-mountable hardware included.