1. a key to SOS distress: in an emergency, press the SOS button, namely to guardian sent a distress message. 
2. double positioning: GPS satellites and dual monitoring base station positioning all real-time positioning tracking. 
3. smart power-saving: GPS closed mode. 
4. remote monitoring, high sensitivity of the microphone, the users in emergency, the voice of the real-time monitoring      equipment around. 
5. two-way conversations: users can call each other, can set up three affection real-time call number. 
6. electronic fence: equipment centered on the map drawn an area, the area of APP and short message alarm immediately. 
7. historical trajectory: path query three months anytime and anywhere. 
8. GSM four frequency system: 850/900/1800/1900 MHZ. 
9. time show that GPS precise GPS clock, don't need to manually adjust the time. 
10. pedometer: steps to measure the user's walking.