Mastertool 5.5" Large Screen Car HUD Head up Display with Obd2 Interface Plug & Play A8 1. Automatic adaptation car models, and can apply for cars in line with OBD II or EUOBD (onboard automatic diagnostic system). Plug and Play. 2. The use of nano-technology to eliminate unwanted reflections and can make display information more sharper. New function:driving mileage measurement 3. Display rich content: speed, engine speed, water temperature, battery voltage, instantaneous fuel consumption, average fuel consumption, mileage measurement, shift reminding, fatigue driving reminding, low voltage alarm, high temperature alarm, speed alarm, engine fault alarm, fault code elimination, free switching between kilometer and mile. 4. Auto power on and off with vehicle started and shutdown, effective protection of the car battery; while retaining the manual switch mode, and more beneficial to control HUD "5. Automatic and manual brightness adjustment mode, driving without glare. This product is for drivers safety, at high speeds, especially in high-speed driving at night, in order to avoid the driver to look down their head to watch the instrument, and decrease car accident."