We are manufacture Sine Wave Output Input Power Factor Correction DC Start-up Bypass Protection Frequency Conversion Startup Function Long Endurance Design Self-Check Function Stable to Disturbance Possible to Collocate with Power Generator Able to Connect with Inductive Load Build-in High Quality Valve-Control Lead-Acid Storage Cell Microprocessor controlled Line Interactive Technology Boost and buck automatic voltage regulation (AVR) Advanced battery management (ABM) Short circuit and overload protection Lightning and surge protection Cold start & energy saving features Communication port and remote monitoring software Input Voltage: 230V or 220V+-25 Output Voltage: simulated sinewave 220V+-10 Frequency: 50 or 60 Hz+-1 Telephone / modem internet surge protection Communication: RS232 port Back up time: 5 - 30 minutes (depending on computer load) cooperate with APC,SANTAK,EMERSON AND SO ON. welcome to contact to me:kayvi01 at hotmail dot com