Simply connect this external battery pack to an existing APC Smart-UPS X to instantly extend the battery runtime of connected devices during a power outage. Simply connect this external battery pack to an existing APC Smart-UPS X to instantly extend the battery runtime of connected devices during a power outage. Please consult your APC Smart-UPS X manual to confirm compatibility with this external battery pack. The battery pack simply plugs into a live APC Smart-UPS, ensuring power availability while increasing runtime capacity. Thanks to the intelligent battery management and precision charging of the APC Smart-UPS, the battery pack maintains the performance, reliability, and lifespan of the UPS system. The APC battery pack offers scalable runtime for the APC Smart-UPS X, allowing multiple battery packs to be added quickly if needed. The battery pack can be mounted in a tower configuration next to an APC Smart-UPS, as well as in a rack-mount configuration below the UPS. Package includes APC SMX120BP external battery pack, installation guide, and rack-mounting brackets.