New GSM Gprs GPS Tracker Tk102-2 Mini GPS Tracking Deivce * 1, Rechargeable Li-ion Battery * 2, Battery Charger * 1, Power Adapter * 1, Water-proof Bag * 1 Geo-fence. The unit will send the message to the authorized numbers when it breaches the district. Movement alert &SOS functionWhen the unit stays immobile in a place for 3-10 minutes, then the unit will reply, it will send SMS "Move" along with a Geo-info to the authorized numbers. It will alarm one time in each setting. When holding the GPS Tracker you can press alarm button to send alert, and your position to the registered phone numbers. Overspeed alert: When the target moves exceeding the speed you setted, the unit will send SMS+Geo-info to the authorized numbers. Audio monitoring: You can dial into the GPS unit and simply listen to the sounds around the unit. Fit for 900/1800/1900MHZ