... extra 4 hours continuous operation if power failureBuilt-in wireless WIFI or GPRS communication for optionSpecification:Processor : ... ’’TFT touch screen face:700fingerprint3000logs100000Back-up Battery: built-in 2000mAh Lithium ion battery(optional)Communication: TCP/IP, ... , Workcode, SMS,T9 input, webserverA&C functions: built-in relay, door sensor, Wiegand outOptional functions: GPRS, printer, ...