Review on Advanced 5” FHD 1080P HUD Display for Car OBD2 Gauge: 3D Reflection, 6 Modes, ECU Data, and Fault Alarm by Brian Page

The device itself is very easy to install. All you need is to connect to the OBD port and turn on the car. The display is quite small: the 5-inch dimension is not a standard diagonal, just a width. Only two data points are displayed at a time. This is fine if you want a simple, uncluttered screen, but it's not convenient to switch between data points while driving. My main complaint, however, is that the device didn't come with a manual, and the settings menu is completely unpronounceable - it takes a hunch to understand what "1 0", "2 -1", etc. means. The Revain site repeatedly mentions how easy it is it's to change the settings using the manual that comes with it, but there's no manual, and unlike most Revain devices, there's no downloadable PDF either, which leads me to guess all the settings and what all the numbers mean. This is even more complicated as it seems that more features have been added to the device than the Revain page lists and Google is not helpful at all. I am returning the device and buying a device with a large display that actually comes with instructions.