Overview: Working based on existing GSM/ GPRS network and GPS satellites,this product canlocate and monitor any remote targets by SMS or GPRS.Also this product canConnect external relay to control vehicle oil or circuit and it can doPower Cut off alarmOverspeed alarmGeo-fence alarm. Note: Please turn on small switch inside SIM card hole after install SIM card. Main Function: 1. GSM quad-band frequency 850/900/1800/1900 Mhz 2. Real time tracking by SMS/GPRS After set the GPS data upload interval for the device, you will can real-time track the device by SMS/GPRS via the APP on your cellphone or the web server on your computer 3.Ignition ON alarm 4.Voice Monitor Send instruction to the device first, then the device will turn into monitor mode, now if you make call to the SIM number in the device, it will pick up your call automatically and you will can monitor the voice around the device! 5. Overspeed alarm When the target moves exceeding the speed you preset, the unit will send the alarm information via SMS to your cellphone or GPRS to web server 6.Geo-fence alarm Set up a geo-fence for the unit to restrict its movements within a district ,unit will send a message to the authorized number when it breaches the district 7. Power Cut off alarm