OBDHUD C3 Plus OBD2 HUD Auto Navigation Projector GPS EOBD Speedometer Head Up Display Car Acceories On-board Computer OBDHUD C3OBD2+GPS OBD2 system and GPS system, dual systems, and has two cables, an OBD2 cable, and a USB cable. OBD2 mode working voltage: 11V~18VDC (12vdc/200mA). GPS mode: when voltage is higher than 24v, please use a USB cable for GPS mode. So C3 is compatible with all carsOBD2 mode including speed, RPM, water temperature, battery voltage, clock, driving time, driving distance, fuel consumption, altitude, satellite numbers, turbine preure,air-fuel ratio, intake preure, KM/H, MPH, data stream...GPS mode supports speed, driving time, driving distance, and satellite numbers...C3 supports speed alarm, RPM alarm, water temperature alarm, voltage alarm, DTCS alarm, and fatigue driving reminder. Brightne can be adjusted according to the environment. Auto automatic light sensitive, 1 for the darkest, 8 for the brightest OBDHUD C3Navigation C3 Plus has additional Navigation Features and can display driving directions. Brightne can be adjusted according to the environment. Auto automatic light sensitive, 1 for the darkest, 8 for the brightest C3 supports speed alarms, RPM alarms, water temperature alarms, voltage alarms, DTCS alarms, and fatigue driving reminders. Please read carefully before placing an order:1. If your car is pre-2004 (for US automakers) and pre-2008 (for European/Asian automakers), the protocol is not compatible. 2. After receiving the package, please test it on your car as soon as poible. If you do not want to keep the device after testing, you can also