For additional runtime, select UPS Systems offer optional external battery packs. Tripp Lite also offers a complete line of PDUs which can be connected to UPS systems in a variety of configurations to: increase the number of UPS outlets, convert UPS outlets from high-amperage to low-amperage output or to allow users to hot-swap the UPS during maintenance without interrupting power to connected equipment. Finally, Tripp Lite offers a complete line of premium enclosures and open-frame racks to organize and secure rackmount equipment, including UPS systems.