Features: Function: Real-time GPS/AGPS/WIFI/4G CAT-1 positioning, SOS alert, voice monitoring, voice recording to app, call family numbers, pedometer, geo-fence alarm reminder, historical track, alarm clock, class mode, power-save mode. Multiple positioning modes: GPS+AGPS+WiFi+Beidou+LBS. Two-way calling: when a saved contact calls, the device allows two-way communication. Device finder: if the device is lost, it can be located using the mobile app. Alarm clock: set via mobile app. Electronic fence: define a boundary on the map with the device at the center; an alert is triggered if the device leaves the designated area. Specifications: Material: PCB SIM slot: Supports NANO-SIM card GPS positioning accuracy: Within 10 meters outdoors WiFi positioning accuracy: Within 50 meters GPS positioning time: Cold boot - 38 seconds (open field), Warm boot - 2 seconds (open field); actual time may vary based on environment Battery: 3.7V 800mAh Size: Approx. 25x35x3.8mm / 0.98"x1.38"x0.15" Note: Please allow 1mm error due to manual measurement. Due to differences in monitor displays, the image may not reflect the actual product color. Package includes: 1 x GPS Tracker