Recently I have been looking at smartphone cases and I am not sure what to make of what the QIN leather means when listed as a material. In some of the products, there is explicitly written QIN PU leather, where PU should mean polyurethane (bicast) leather which seems to be using animal leather but most of the adverts omit the PU part.
To give an idea, I was looking at covers for ASUS Zenfone 3 (ZE552KL), such as this one, but for future reference, any cover that shows up when searching for Nillkin QIN leather case.