1. Build-in GPS Vehicles locator 2. Support 4-frequency GSM 900/1800 MHz. (850/1900 Optional). Works worldwide! 3. High sensitivity, new technology and latest GPS chipset! 4. Excellent for fixing the position even at a weak signal status. 5. Work well even in areas with limited sky view like urban canyons. 6. Support Cut Oil and Electricity Function. 7. Fast Signal Acquisition.Support alarm. have Geo Fence Function ,can set at least 100M. 8. Support single location and continuous tracking 9. Support alarm. have Geo Fence, Can set up at least 100M. 10. Support quick dialing buttons for 3 preset phone number 11. Support check location by SMS and Internet 12. Locate the locator holder by the mobile phone via SMS 13. SOS button send out exact location for immediate rescue/action. 14. Lead leads to a total of 4 lines, were red +12 V power supply、Black GND、orange external SOS line、white NC.