VJOYCAR New Speedometer HUD GPS Digital Speed Meter MPH Speedo Head Up Display f
If your car has a USB port, pls plug the USB cable to USB port; if your car doesn’t have a USB port, then give it a car adaptor. Plug and Play. 【On/Off automatically】 When detect car ACC is on, it will be on and display the driving speed in big fonts; When car ACC is off, it will be off automatically because it doesn’t have internal battery.