HUD DescriptionHead-up display, the product features a high-definition display that shows the car's digital driving speed directly on the display. This HUD is also free from ghosting in the midday sun and is clearly visible in both day and night. GPS speedometerThe speedometer uses GPS satellites to collect speed data independent of the car engine and does not damage the car's circuit board or OBD port. The product can be used on a wide range of vehicles such as pick-up trucks, scooters, golf carts, buses, boats, fires, cars, and all other vehicles on the market. Easy installation: the product is very easy to install, no buttons, no setup required. the USB cable is plug and play. If your car has a USB port, plug the USB cable into the USB port; if your car does not have a USB port, give it a car adapter. Automatic on/offBuilt-in vibration sensor, when motion is detected in the car it will be switched on and the driving speed will be displayed in large font; if it remains 100% stationary for more than 3 minutes it will be switched off. When it is off, there is no power consumption. After sales serviceWhen using it for the first time, it takes 10-30 seconds to get a GPS signal.If you receive a faulty product, you do not need to send it back to Amazon, you contact us directly via Amazon's purchase history and we will replace it with a brand new one.