The APC Back-UPS Pro UPS systems provide battery backup and surge protection. Ideal for your home, home office, or small business. The Back-UPS Pro models come equipped with premium features, including extended runtime and power capacity for your critical electronics. They reserve capacity and runtime for connected devices that need to switch to battery operation in an emergency. Less critical devices are only protected from surges. Automatic Voltage Regulation (AVR) automatically steps up low voltage and reduces high voltage to levels suitable for your devices. It instantly corrects low and high voltage fluctuations and is compatible with Active Power Factor Correction (PFC). It protects your devices and valuable files from "backdoor" surges that travel through data lines without affecting internet speed. A quick battery replacement is possible, and compatible batteries can be found in the accessories list. Expected battery life: 3-5 years. Information about the power supply and UPS conditions can be quickly and easily read on the LCD display.