Key Specifications/Special Features: Real-time locating and tracking. Sent a SMS to the GPS tracker and it will return you the longitude, latitude coordinate and moving speed of the tracking target, then you can find out the location accurately through the free Google Map or other map software Geo-fence: It will send an alert to the authorized numbers when it breaches the restricted area that you set up before Two way talking communication: You can talk with the tracking target via the GPS tracker just like a cell phone and also can listen to the sound around the GPS tracker in 5meter secretly SOS button: Press the SOS button and the GPS tracker will send a help alert and exact location to the authorized numbers for immediate rescue Overspeed alert: It will send an overspeed alert to the authorized numbers when the tracking target moves exceed of the restricted speed.