Features Multiple Positioning Mode: GPS+ AGPS+LBS+Wifi. Worldwide GSM+GPRS 4-frequency System: 850/900/1800/1900MHz. The user's specific location can be inquired through the cell phone APP or the computer. Designate an area on the map by setting the device as the center point and the alarm will be triggered off immediately once the user of the device goes into or out of this area. Inquire the moving routes of the device in the past 3 months anytime and anywhere. In case of emergency, press the SOS button and the device will send out the call and message for help to the guardian. The lost device can be found through the APP on the cell phone. With the highly sensitive microphone, the sound around the device can be heard in real time in case the emergency happens to the user. The device can be turned off through the APP on the guardian's cell phone. The device can be restarted through the APP on the guardian's cell phone. The device turns off/on the GPS and data upload in the time range specified through the APP on the guardian's cell phone.