Today I received my "Chinese" wing mirror extensions.
I had previously installed the SlingMods extensions, so took the opportunity to compare them both.
The Chinese version had a slightly longer pitch between the holes and lifted the height by the same amount as the SlingMods product.
The Chinese detention came with two allen bolts, where as the SlingMods design had a hex head, with a flanges brace. Both designs need tightening down with some force. The SlingMods' version was far better, as it had a much greater surface area, between the bolt and the extensions. I suspect that the Chinese one could, in time, work loose much easier, however I did not experience it. The holes in SlingMods' design are an extremely close tolerance, with slim socket wrench heads and could be bigger, however I did get everything to work with a little effort.
Both options improve the vision, from the cockpit, fare more than I had expected. This is of particular importance to me, using a left hand drive vehicle on British roads
Both do the job we and give an exceptional improvement to the standard setup.
The Chinese detention may work loose, with time.
The SlingMods version looks better, as the Chinese one is a little too slim.
The Chinese adaptor retails at $10 & the SlingMods one is $40 right now.
So which one would I recommend?
The Chinese arm, is far cheaper and would do the job, however the SlingMods version is fat more attractive and better made, with a more secure bolting down design using the flanged, hex head, bolts. Therfore, even at the much higher price, SlingMods wins out.