The Vertiv Liebert PSI5-72VBATT is valve-regulated, lead-acid UPS external battery cabinet designed for use with these UPS models PSI5-3000RT120 and PSI5-5000RT208. The Vertiv Liebert PSI5 is a compact rackmount or tower, AVR line-interactive UPS system designed especially for IT applications such as network closets and small data centers. It supports advanced pure sine wave output on battery to safeguard critical IT equipment and business electronics. It also provides reliable power protection for servers, critical nodes, network workstations, large network peripherals, network routers, bridges, and other electronic equipment.