A100S Car HUD Head Up Display OBD2 EUOBD Overspeed Warning Auto Electronic Voltage Alarm Better Than A100 HUD A100S HUD Feature: 1. Light sensor for brightne automatic adjusting. 2. Main 4 function can be display: SpeedWater temperatureBattery voltateMilage 3. Main 6 options to alert: Over speed: 120KM/H High temperature: >120 degree Low battery voltage: <11V Rest Alarm: driving time> 4 hours High RPM Alarm: low speed with high RPM Beep Alarm 4. HUD (Head-Up Display) projects driving data without requiring drivers to look away from their usual viewpoint. 5. HUD automatically adjusts its brightne level, so its projections are clearly visible in direct sunlight or at night. 6. Alerts you if you exceed the speed limit by setting Over-speed buzzing alarm alarm, engine rpm, water temperature, voltage, instant fuel consumption, average fuel consumption, mileage, shift remind, fatigue driving remind, undervoltage alarm, high water temperature alarm, engine failure alarm, KM/MILE free shift, etc. 7. Projects a lot of driving information onto a transparent film on your windshield such as speed, over speed 8. Easty installation to work 9. Speed Unit: KM/H; MPH