Aweek&reg; GSM Magnetic Door Alarm Wireless Window Sensor Alarm Voice Detector Remote Control Anti-Theft Burglar Home Security/ Remote GSM Location GSM Real time Tracking Function (White) This magnectic voice alarm use GSM module with multisensor components owning magnetic and voice sens By binding your phone number with this magnetic vocie alarm host inserting into another SIM card fir You can bind 5 phone numbers(at most) with this alarm host so that it adds the possibility of findin Provide free remote location function, you can know where your car or something else is Operating frequency: 850/900/1800/1900 MHz. (NOT support CDMA cards)