Protection for small electronic equipment and personal computers. The ESC series offer the highest power capacity and the best equipment protection around. Not only do they protect against blackouts, sags and surges, but with the added feature of AVR (Automatic Voltage Regulator), these UPS products ensure that only clean and safe currents reach your equipment. What is AVR? AVR is a feature that corrects under and over voltages without draining the battery, thus providing extended battery life and, most important, allowing the UPS to provide high quality power during unacceptable voltage fluctuations.