Extremely low return noise and no disturbance to talking quality. Use-friendly interface, LED simulative display and computer screen display of inverter operation status. RS232 port, smart power management software, automatic file saving and shutting down at power abnormalities. Special charging system design for better protection of battery life. Short circuit, overload, over voltage and low battery protection. Compatible with generators and suitable for harsh environment where power voltage is extremely unstable. With standard on-line structure (three ports)and can be used as UPS. Specification