... & Magnet Pin & Free service charge,GSM weblink,SMS&Calling trigger,GPRS upload!Product Description Welcome to use this Real Time GPS ... and GSM, the tracker sends the present location information through GPRS to internet server, so that user visit the website www ... free tracking platform- Working method: locate with GPS, upload with GPRS- SIMCOM GSM module (4 frequency) & Taiwan GPS module (Sirf or ...