KingNeed Universal GPS Heads Up Display Car GPS Speedometer Digital Speed Projector Windshield Projection with Over-speed Alarm For All Vehicle Head-up display - Projects the driving speed on the windscreen. Display MPH or KM/h. Keep your eyes on the road. Safe Alarm- Overspeed Alarm & Fatigue Driving Alarm to ensure your safe in long distance driving. Green Light Display with 3 Display ModeNormal stand-up display, Reflecting display,Upside-down display Mode. Auto adjust brightness through sensor for Day & Night driving. Green color speed display, easy on your eye. Green Light Display with 3 Display ModeNormal stand-up display, Reflecting display,Upside-down display Mode. Auto adjust brightness through sensor for Day & Night driving. Green color speed display, easy on your eye. Plug & Play- Power through vehicle cigarette lighter. No professional installation is required. Compatible with all Cars & Trucks. Use GPS signal guided calculation. No wiring needed to the VSS (vehicle speed signal). Head-up display - projects the driving speed on the windscreen. Driving time and mileage calculation and display Easy Setup--Plug &amp; Play- Power through vehicle cigarette lighter. No professional installation is required. Compatible with all Cars &amp; Trucks. Use GPS signal guided calculation. No wiring needed to the VSS (vehicle speed signal). Display MPH or KM/h; ( The default speed unit is KMH. To switch it to MPH, please follow IV. in Operation Guide. ) Auto adjust brightness through sensor for Day &amp; Night driving; Vehicle driving speed display. Green color speed display, easy on your eye; Over-speed Alarm setting.(This function can be on or off ).Overspeed default setting is 120KM/H or 120MPH. Just need press the up  or down&#034;to adjust it. When over-speed alarm is active, it will beep in  3 times to alert the car driver. If no need overspeed alert, adjust it  to a impossible speed. eg:999MPH; System will start calculating total driving time and mileage when device is powered on. Parking time is not included in the calculations in order to increase the data accuracy. Mileage less than 1KM will be considered as invalid data Once the vehicle stops for a few seconds, you will see data displayed on the screen in order as total mileage, and then the total driving time in minutes. All driving data will be cleared once the vehicle is engineoff, and system will start the calculationagain when the car power resumed. Press Enterbutton, you will seenumbers 111 222 333 are shown on the screen1 11 refersto Normaldisplay mode, content will be shown on the screen in normal condition. 222 refer to Reflectingdisplay mode, content  will be shown on the screen in opposite side in order to be reflected on  the windscreen correctly 333 refer toUpside-downdisplay mode,  content will be shown on the  screen upside-down in order to fit the  specific position in the car,  such as behind the front rearview mirror.  (for certain vehicle  modelsonly)