... : GSM 850/900/1800/1900Mhz GPS Chipset: GPS SIRF-Star III chipset GPS Sensitivity -158Db GPS Frequency: L1, 1575 Global GPS Tracker with Two Way Calling + SMS ... provides GPS speed data for object velocity. Works at an altitude of 18,000 meters (60,000 feet) 3 buttons (SOS/B ... mode 3 LED lights to show power, GPS, GSM and other operation status SOS button to send SMS help message to paired ...