working voltage 8VDC~36VDC Working current 50mA~160mA GSM module inside contain frequency GSM 900/1800 inside contain frequency GSM 850/900/1800/1900Mhz (can tailor) Communication protocol UDP/TCP(can customize) GPS module GPS S IRF-Star III CMOS chip group GPS sensitivity -159dBm GPS frequency L1, 1575.42 MHz C/A coding 1.023 MHz chip rate Channels 20 channels for tracking Position accuracy 10 meter, 2D RMS Speed accuracy 0.1 meter/second Time accuracy GPS synchronization Default date WGS-84 Recover Average 0.1 second Hot start Average 1 second Warm start Average 38 second< Height limit 18,000 meter (60,000 feet) max Speed limit 515 kilometer/second (1000 knots)max Acceleration limit Less than 4g Expansion peripheral Peripherals can be accessed by an extension (such as: Handle / scheduling screen / camera etc.