Fault code clearing: When the engine warning light on the dashboard indicates a fault, you can clear the fault code yourself with this unit, without a trip to the repair shop. Easy to read: The tachometer uses an analog needle to show engine RPM at a glance; the display also presents vehicle speed, time, and other data for quick reference. Ten interface options: Ten interface styles with an easy switch. LCD meter mode provides a clear fault-code display and enables reading the data stream. Easy installation: Includes an OBD2 cable that plugs into the vehicle's OBD port. It does not modify wiring or damage the car’s finish. Simply connect the OBD port to the HUD with the included cable, then place the HUD on the dashboard or stick it to the windshield. Use scenarios - Daily driving: Monitor engine RPM and speed at a glance, with quick access to clear minor fault codes if needed. - DIY diagnostics: When check engine light appears, read data stream to understand engine behavior and decide if a professional service is required. - Comfortable viewing in varying conditions: Switch to the LCD meter for clearer readability in bright or dim environments, and position the HUD on the dashboard or windshield for optimal visibility.