ONE KEY SOS! 1. GSM Channel: GSM 850/900/1800/1900Mhz Quad bank used in worldwide . GPS Sensitivity: -163dB 2. Besides SOS function and shortcut calling to guardian this smart GPS tracking watch also can send the location information to mobile and computer quickly by sending message or through GPRS. Also you can get the tracker location information by online tracking service platform. 3. This GPS gadget comes with one SOS call button and two additional buttons to call mom dad your sister or the home or office. You can speed dial three phone numbers from this GPS cell phone wrist watch with just a push of a button. 4. GPS Datum: WGS-84 5. Get watch's position:Service platform Mobile phone message and a variety of ways