Specifications: 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