In spite of the low cost, the design of this unit's circuitry is fairly robust -- better than some DIY designs you will find on the web.FTDI usb to serial interface IC (FT232BL), and LM393 dual voltage comparator for dual K line level conversion (only). (OK)The main drawback is that the supplied software is useless (ancient), and the instructions are useless (non-applicable to any recent versions of windows). It is also understood that there is no support.Initially installing the USB driver from FTDI web site seemed to work, but did not. Strongly consider using the latest drivers from windows update site, which work properly with VCDS lite and (of course) are signed and work well with Windows 7 (in my base 64 bit version also).Also when checking connection using VCDS lite, "options" (per instructions), make sure you do this _physically_ _connected_ to car's OBD port, and _not_ with other serial ports (which will falsely pass "test" in VCDS lite "options" pane). These are the two most common setup/install problems you may encounter.There is no support for this product or the software you might run with it, so take care to follow the directions precisely. If you do so, you will have a good chance of this working with recent versions of windows and vcds-lite (or other free/share ware for VW/Audi OBD).Where my sample fell short is in proper function; tested this with multiple computers and known-compatible cars (that work with other OBD-II readers); it did not ever establish a connection to the car. Software used included the VCDS freeware version, as well as two other open source tools.When checking the connections and soldering under microscope, I found that the OBD connector (J1962) that connects to the car jack was poorly soldered. Otherwise the device appears well put together.Amazon processed a refund properly; boost review a star given huge value and good fallback if all else fails.BTW purchased the similar, but better-built cable, from ecstuning for about 3x the total cost. Very happy with that bit of hardware.