Quad Band GSM Modem: 850/900/1800/1900Mhz (worldwide use)

Just like 8 single-channel equipments work at the same time

Can insert 8 sim cards (big or small)

GSM Modem supportchange imei by AT command

Send about 600 sms per port per hour

Connection with the computer through a data line can be integrated with serial 8

Compatible with OS: Linux / XP / Vista / WIN7 / WIN8/WIN10 etc.

 How to change the gsm modem imei

1. Use putty to login the module
2. Input the at command ATE1 to echo display
3. //WRITE:AT+EGMR=1, 7, "359231033480797" this at command will change the module imei to 359231033480797, and pls notice that you have to use the correct imei number if not the imei will be changed back to factory after reboot.  

 How to make a call

1. Login the module and plugin the earphone in the module.
2. Input the at command ATE1 to echo display
3. Use at command ATD to make a call. Such as you want to dial 10086 then you need fill at command ATD10086; then you can hear the ring from the earphone. You can use at commandATH to handup a call.

Notice:

1. This gsm modem will blink every 2 seconds when it works normally.
2. It blinks one time one second without signal. If like this please change the working module's sim card to this module to check.
3. Please turn off the module power to change the sim card.