Offering protection for PC servers, security systems and all necessary equipment for power users, the Opti-Ups ES-C series is the perfect entry level UPS for your computer system. The ES-C series not only protects against blackouts, sags and surges, but with the added feature of AVR (Automatic Voltage Regulator), these UPS products also ensure that only clean and safe currents reach your equipment. AVR is the feature that corrects under- and over-voltages without draining the battery, providing extended battery life and allowing the UPS to provide high quality power during unacceptable voltage fluctuations.