1. Automatically turn on and off as the car starts and stops. 2. Alarm functions Improve driving safety: (1). Overspeed alarm:Alarm when the vehicle speed reaches the set default value of 150KM/H (30-250 setting) (2). Fatigue driving: Reminder after continuous driving exceeds the default value of 4.0 hours(1-8h setting) 3. The altitude is collected by satellite and is not affected by naturul factors such as weather.Very high positioning accuracy. 4. GPS Compass: Display the forward direction while driving,so that your journey is not yaw. 5. Display information: speed, time, number of satellites, driving distance, driving time, compass direction, driving direction angle, altitude, acceleration time per 100 kilometers 6. Alarm function: fatigue driving reminder, speeding alarm