It's an ELM327 device, and how good it is depends on the software you use.
I bought one in some months ago for use on a Triton ute, and before I passed it on I tried it on my Mk7 TDI.
The actual item (a bluetooth to laptop/tablet/phone interface) cost around $A15 delivered and I searched for better software to suit the Triton, which eventually was around $60.
It read most segments of the Golf, but I didn't try changing anything (the software was sort of universal OBD11 and intended for service use, but didn't look too useful on Euro cars.)
Unfortunately the lad it was for is no longer with us and the ute has been sold, so I can't tell you much more — but you're paying far too much shipping on that one. Do an Ebay search.
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