1.GSM900/1800Mhz (850/1900Mhz optional) 2.GSM voice communication,choose any position on users' own to enhance signal intensity via short or long Tel-line. 3.Provide feedback signal for payphone,able to connect Toll set for payment count. 4.Two output ports Able to connect regular fixed telephone(desktop phone) or cordless phone,easy installation. 5.Support Mini-PABX to connect with GSM 6.External backup batteries supporting 4 hours talking and 24 hours stand-b,easy installation.able to connect power supply for intelligently charging. 7.Lock SIM card in software and hardware. 8.Support internet function,data,GPRS,fax. 9.Prefix IP number auto-dialing. 10.Inner antenna with exquisite appearance. 11.Support calls forbiddance for incoming and dialing. 12.The other regular phone's functions,such as "call records"can be met by connecting to a regular phone. 13.New module with good quality and steady performance.