GBSELL Mini Vehicle GSM GPRS GPS Tracker Car Vehicle Tracking Locator TK102B Simply insert a GSM sim card into the GPS unit. Whenever you call the unit it will respond with the coordinates of its location thru a SMS message. You can then use these coordinates on any mapping software (for example Google Earth) which will show where exactly the unit is located. This Cutting-Edge GPS tracker is designed for advanced tracking/monitoring, especially for vehicle tracking using GPS, GSM and GPRS technology. This is particularly useful if your vehicle, pets, child or your belongings have been stolen. Time to enjoy the benefits this GPS tracker brings! No monthly service charges to be paid to the call center;Compact size, easy to carry, hold and hide. Package Content: 1 x GPS Tracker;1 x 3.7V / 850mAh Li-ion battery; 1 x Cable;1 x User Manual