The unit is powered by automotive battery, and should be installed inside a vehicle (preferably a place where it cannot be seen, for example, under the car seat). It runs on the latest GPS SiRF III chip-set, a sophisticated GPS microchip embedded into the heart of the tracker which continually reads its own location from low orbiting global satellites and then utilizes the GSM/GPRS infrastructure operated by your network provider to transmit its current location to you.