these units are designed to supply backup power and power conditioning of a home pc, or a small of. ce environment. . avr (automatic voltage regulation) buck and boost system to hold the mains voltage at 240v over a wide range, before the battery kicks in. this prolongs battery life by a large amount . australian standard sockets on the rear for ease of use, 2 on ups650d and 4 on ups1000d and ups1700d . line interactive design, step sine wave design . useful display showing battery capacity and load graphically, overload, charge, fault and normal . micro-processor controlled . smart rs232 communication, port and software (included) for automatic computer shut down . alarm function by buzzer and display . cold start function . fax, modem or telephone protection port . overload and short circuit protection on the output