Main Feature: Support GSM 900/1800 MHz. Works worldwide! High sensitivity, SIRF Star Ⅲ low power GPS chipset! Excellent for fixing the position even at a weak signal status, work well even in areas with limited sky view like urban canyons Fast Signal Acquisition Support single location and continuous tracking Support alarm, have 3 preset phone number Support check location and real-time and historical trajectory by SMS or Internet SOS button send out exact location for immediate rescue/action. Support cut-off electricity and oil function and recovery command Lead leads to a total of 4 lines, were red: +12 V power supply、blue: GND、between yellow line and blue line connect external SOS button