1.Head-up display the driving speed. 2.Driving time and mileage calculation and display. 3.Over-speed alarm setting. 4.Fatigue driving alarm. 5.Altitude display. 6.Local time display with auto timezone adjustment. 7.Easy Setup- Plug and Play- Power through vehicle lighter. No professional installation is required. 8.Compatible with all Cars and Trucks. Use GPS signal guided calculation. No wiring needed to the VSS (vehicle speed signal). 9.Display or km/h. 10.Auto adjust brightness through sensor for Day and Night driving. 11.Green color data display, your eye. 12.Total mileage display after car stops. parameters: 1.GPS positioning time: 1 to 5 minutes in the open air (The weather will affect the positioning time). There is no GPS signals indoors. 2.Speed deviation: Since the speed data comes from the GPS satellite, slight deviation is unavoidable. 3.Input voltage: DC 5V Input current: DC 50-120mA Working temperature: -30 to 70 degree 4.Driving data deviation is around 2 percent 5.All driving data will be cleared when power off except the total mileage. Colour:black Material:plastic Package Contents: 1 x HUD Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is 1-3cm.