Sourcingbay Car HUD Vehicle-mounted Head up Display System OBD Projection Display Car Speed with Maximum Speed Record/ Gear Shift Reminding / Over Speed Alarm / Water Temperature Alarm / Voltage Alarm OBD II (vehicle automatic diagnostic system) Plug and Play models Vehicle speed, engine speed, water temperature, fuel consumption showed Can record cars driving over the maximum speed speed single-stage and fourth paragraphs of alarm modes, more conducive to traffic safety automatic and manual brightness adjustment mode