Simply connect this external battery pack to an existing APC Smart-UPS X to instantly increase the battery runtime of connected equipment during a power outage. Simply connect this external battery pack to an existing APC Smart-UPS X to instantly increase the battery runtime of connected equipment during a power outage. Please consult your APC Smart-UPS X manual to confirm compatibility with this external battery mount. The battery pack simply plugs and plays onto an in-service APC Smart-UPS, ensuring power availability while increasing runtime capacity. With the APC Smart-UPS' intelligent battery management and precision charging, the battery pack maintains the performance, reliability and lifetime of the UPS system. The APC Battery Pack provides scalable runtime for the APC Smart-UPS X, allowing multiple battery packs to be quickly added as needed. The battery pack can be mounted in a tower configuration next to an APC Smart-UPS or in a rack-mount configuration underneath the UPS. Package includes APC SMX120BP external battery pack, installation guide and rack mounting brackets.