Internet positioning service center, used to receive and send positioning information * GSM /GPRS modem supports Quad frequency bands, i.e. 850/900/1800/1900 MHz * High-sensitivity, new workmanship and the most advanced GPS chip * Supports single positioning and continuous tracking / Supports alarming and remote monitoring / Supports fast dial button * May monitor without disturbing the tracked person and realizes real-time tracking / Can position the holder by call or SMS