1). Aluminum alloy housing of brain unit 2). Industrial GSM module. Working Fequency: 800 Mhz/ 900 Mhz / 1800 Mhz /1900 Mhz 3). No limited for alarming distance, ramble all over the world 4). Alarming phone auto-dial directly to your phone at hand, 3- alarming phone numbers 5). Built-in backup battery, make sure that the system is working properly once the power supply is cut off 6). Operating by phone, as there will be an voice to indicate you for operating, such as alarming phone number or system enter password amendment. 7) No need to memorize any operation indications, for there voice operation guidance. 8) Wireless dialing device built-in for hand free communication. 9). Real-time car inside situation monitoring. 10).SMS operation