Here is a quick review of the Yintal adjustable razor, which exists in many different versions (black, faux bronze, rose gold/black, etc). Although, not many information are available about this razor, it seems, however, that it has been designed by Weishi. Mine was bought from the Yintal store on Aliexpress (about £22, received 2 weeks later; with a bit of luck, it is even possible to find it discounted down to £15 delivered).
The butterfly mechanism resembles those used in Gillette adjustable razors of the 60-70s, but adjusting the settings is not incremental (which allows some fine tuning). In terms of behaviour, aggressiveness is somewhere in the neighbourhood of the Slim and the like; adjustment is done by tightening the ring under the razor head. Also, there are no slots or gutters to evacuate the excess of water or lather.
The main difference is a longer and heavier handle, providing a rather good grip (razor weighs 107g by the way).
As for shaving, it is good, like really good, but boringly good… To be honest, my first shave with it was almost frustrating in fact.
Do not expect any excitement, even if you venture in higher settings. Experienced shavers will certainly adjust very quickly (it took me 30s to find the right setting at 3, and then after a few shaves I increased to 4, which seems to be the perfect one as of now). No thrills, definitely; but a razor that would likely drive a beginner safely to his comfort zone.
Actually, I think of this Yintal adjustable as a reinterpretation of the classics. The manufacturer has simply put together the good recipes of adjustable razors of the 60s and improved them a little (better grip, more weigh, no incremented settings). Therefore, no innovations, just a plain functional razor, with a generic (yet efficient) design that provides comfortable shaves.
EDIT: the razor is supposed to be made of "pure" brass, according to the vendor's description.