HUD short for Head Up Display,the main function is to display the car dashboard information (e.g.speed,RPM,water temperature,voltage,trip distance etc ),and keep the driver eyes always on road to avoid the dangerous of lowering down head to read the dashboard. Features: Multi function: speed,engine RPM,water temperature,voltage,driving distance: speed,engine RPM,water temperature,voltage,driving distance. Alarm: water temperature alarm, voltage alarm, gear shift reminder, overspeed alarm, fatigue driving reminder, engine failure alarm. Exquisite design. High-definition display lens, not affected by external light. Plug and play, easy to operate. GPS mode display information: vehicle speedtravel time, satellite time, altitude, satellite number, driving direction, single mileage, voltage, acceleration test and brake test. HD display screen: multiple UI can switch different pictures, interface digital color can be freely adjusted. The HUD can eliminate the trouble code displayed on the engine dashboard. No need for professional equipment. Early warning of vehicle breakdowns caused by high water temperature and low voltage. OBD + GPS dual mode is applicable to all models. Specifications: Model: P17 Screen size: 3inch Display Information: Vehicle speed/water temperature/voltage/fuel consumption/speed/single mileage/total mileage/travel time/travel direction/search stars number altitude/time/intake pressure/oil temperature/air fuel ratio/turbine pressure/intake pressure/acceleration test/brake test/data stream reading Alarm: RPM AlarmWater Temperature AlarmLow Voltage AlarmFaulty Code Alarm, Overspeed alarm, Engine fault alarm (free switch between centigrade and Fahrenheit) Environment temperature: -40+80 Atmospheric pressure: 86-106 KPa Environmental noise:Alarm sound level: =30dB (A) Working voltage: 11V ~ 18Vdc (12Vdc / 200mA) Product size: 12.5*6.8*3.1cm Package size: 14.5*10*7.5cm Package weight: 340g Package List: 1 x HUD Main Unit 1 x OBD Cable 1 x User Manual 1 x Non-slip Mat 1 x Small suction cup