This SmartOnline rack-mount online double-conversion UPS system provides uninterrupted battery backup and AC power protection against blackouts, brownouts, surges and line noise that can damagevaluable IT equipment or destroy data. An included stepdown transformer converts your UPS, utility or generator’s 208V high-voltage input to 120V low-voltage output to allow connection of a wider range of components. The field-replaceable, hot-swappable valve regulated lead acid (VRLA) battery modules allow you to work through short power failures and give you enough time to safely save files and shut down your system in case of a prolonged blackout. Automatic restart after power outages reduces costly on-site visits. You can also connect up to four extended battery modules (BP180RT, sold separately) for hours of extended runtime.