We also have models with PSTN and fax funtion based on this unit.
And this device supports only 1 SIM card, we have devices support 2/4/8 SIM cards too.
Welcome to contact me if you have interest.
GSM FWT-8848 is a GSM to Analog converter(single port, insert 1 SIM card only),
the device can produce a FXS line to allow a regular phone to be connected and used just like a local landline(PSTN) except your calls will go out the GSM network.
This device can both receive and make calls.
The main application is connecting the RJ-11 FXS line:
to connect ordinary telephone set for voice call;
to connect PBX for call extensions;
to connect billing systems for public phone use;
to connect VoIP FXO gateway to realize VoIP call termination;
to connect alarm system for security purpose, etc.
It is not a VOIP gateway, nor a GSM+VoIP gateway.
It is a GSM Fixed Wireless Terminal that produces an analog FXS phone line.
Features
1) It is a 1 channel GSM fixed wireless terminal which has 2 RJ-11 outputs for extensions; 2) It can connect with ordinary telephone set, PBX , VOIP Gateway, billing meter etc. ; 3) Dialing tone frequency:450hz; 4) Employ Industrial module to make; 5) Can adjust dial interval from 0.5 sec to 9 secs by setting up from telephone set; 6) Can adjust voice volume by setting up from telephone set; 7) SIM card supported (1.8V, 3V); 8) Caller ID display; 9) DTMF dialing; 10) Bell signal; 11) Polarity reversal; 12) The RJ-11 socket which connect the phone or billing system for metering purpose; 13) Antenna socket(SMA); 14) IP presetting; 15) Working Status and Signal Strength by LED indicator; 16) IMEI Change(optional). 17) Back up Li-ion battery 7.2V 1300mAh(optional), standby time: 24hrs, talking time: 2.5hrs.