Smart UPS models have long been considered the benchmark for all network and server UPS's. Smart UPS feature a 16-segment LED display, extended range automatic voltage regulation (AVR), and pure sine wave output on battery. Additional manageability options are available through the Smart-Slot interface, which is an internal slot for the installation of optional accessory cards. The extended run Smart UPS XL has the capability to add external battery packs to scale runtime from minutes to hours typically needed for converged voice and data networks. The entry level Smart UPS SC is an economical choice for small and medium businesses looking to protect small switches, networking devices and point-of-sale (POS) equipment.