Description: Multiple Positioning Mode: GPS+ AGPS+LBS+WIFI + TF Card and APP Voice Recorder Worldwide GSM+GPRS 4-frequency System: 850/900/1800/1900MHz Automatic Time Update: Precise GPS time service and no manual time adjustment is needed Track: The user& 39;s specific location can be inquired through the cell phone APP or the computer Fence: 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 PlayBack: Inquire the moving routes of the device in the past 3 months anytime and anywhere SOS: In case of emergency, press the SOS button and the device will send out the call and message for help to the custodian (long press power button 4 seconds) Voice: With the highly sensitive microphone, the sound around the device can be heard in real time in case the emergency happens to the user Remote Power-off: The device can be turned off through the APP on the custodian& 39;s cell phone Remote Restart: The device can be restarted through the APP on the custodian& 39;s cell phone Intelligent Power Saving: The device turns off/on the GPS and data upload in the time range specified through the APP on the custodian& 39;s cell phone. Specification: Material: Plastic S3: Size: 40x24x12mm/1.57x0.94x0.47 inch 400mAh Battery Stand-by time: 4 Days Working Time: 2 Days S7: Size: 57x24x16mm/2.24x0.94x0.63 inch 1000mAh Battery Stand-by Time: 10 Days Working Time: 5 Days Package Includes:(2 Pack) 1 Piece GPS Tracking Locator