G4 G4S GPS Head-Up Display Car Electronics HUDProjector Display Digital Car Speedometer Accessories For All CarsTips:HUD Drive: The best head-up display for any car1:Head-up display (HUD) for everyday commute to stay focused and connected while driving2:Installed on the dashboard at one time, the cables are concealed, and the appearance is the same as the original car, The machine does not damage the car, and use safe.For all models, the connection is a USB interface.5vThe original car is not damaged, the smart is started to stop with the car;HUD works: Receive the data from the car and display it on the machine.What is the difference between G4 and G4S?Usually, users prefer to buy a machine with G4 ambient light, which has a good-looking picture and many functions. G4S mainly displays a simple mode: the function of speed + time.---The G4 machine chip uses the latest upgraded hardware, so the G4 will position the satellite faster than the G4S based on GPS.G4 Function:1: speed2:driving direction guide3: 5 color mood lights4: Simple mode display5: Ambient light acceleration display6: One-key switch between kilometers and miles7: Automatic photoreceptorCall the police:1: Overspeed alarm2: Fatigue driving reminderG4S Function:1: Vehicle speed2: TimeCall the police:1: Overspeed alarm2: Fatigue driving reminder Alarm functions Improve driving safety