1. Collect real time speed from GPS satellites
2. Driving time and distance calculation and diasplay
3. Play and plug: power through vehicle cigarette outlet jack, no professional installation is required
4. Display MPH or KM/h: simple push button set up
5. Auto adjust brightness through sensor for day and night-time driving
6. Over-speed warning: 3s alarm beep and display flash will wran driver 93 beeps for over speeding alert