Safe Alarm: Overspeed Alarm & Fatigue Driving Alarm to ensure your safe in long distance driving. The details pls refer to below "Product Description Section" Key Incompatible for mation Display: Head up display the speed. -Display MPH or KM/h -Driving Time, Altitude -Distance Calculate and Display -Car Clock -Automatically Identify Time Zone -Accurate GPS Local Time Display, let you know the real-time key incompatible for mation compatible for your trip. Green Light & Big Number Display: large Screen & Green light display will protect eyes of driver, let driver feel more comcompatible for table, especially compatible for long distance driving. Plug & Play: -This HUD calculates & display the real-time speed via GPS. -No Need professional installation, No wiring needed to the VSS vehicle speed signal, Compatible with all cars & trucks, C80 also Compatible with motocycle & bicycle; Non-skiding: With a rotatable holder & strong sticker stand, can fix HUD to your car console or windshield, prevent the HUD from skidding.