Build-in GPS personal locator. GSM /SMS communication or GPRS TCP/UDP connection . ?Works worldwide! Support 4-frequency GSM 850/900/1800/1900 MHZ.(Optional) ?High sensitivity,New technology and latest GPS SiRF-Star III chipset! Excellent for fixing the position even at a weak signal status. Work well even in areas with limited sky view like urban canyons . ? Compact size, and smaller than one name card. Easy to hide ? Very Low power consumption ? Fast Signal Acquisition ? Support single location and continuous tracking ? Support location triggered by tracker ? Support location triggered by authorized cell phone ? Support alarm and remote monitor ? Support quick dialing buttons for 2 preset phone numbers ? Support check location by SMS and Internet ? Monitors can track the person without interfering him, LIVE! Real-Time tracking! ? Locate the locator holder by the mobile phone via SMS (short messaging system). ?SOS button send out exact location for immediate rescue/action. ? Geo-fencing to restrict movement to a defined radius. ? No monthly service charges to be paid to the call center