I've been using K&F products for a while, but I had never tried their microfiber cloths.
These have also proven to be very good, they clean from dust already in check (but it's better not to do it!) and with a product to remove dirt (I feel comfortable with what you see in the picture ), clean them perfectly without leaving any lint or traces of dust. A trick that can be useful for those who use cleaning products is to spray or pour them on the cloth, not on the surface to be cleaned: in addition to saving the product, you also avoid the dangers of penetration.
There's not much to say, I think the photos on my phone before and after cleaning explain it better than I could in writing.
Of course, they can also be used for other things: TVs (one cloth was enough to clean a 44-inch TV), PC screens, glasses lenses and they also say optics, but for these applications of specific products.
I chose the 20 piece set because I like to have a good supply, but I think the 10 piece set is ideal: once 7 or 8 cloths have been used, they can be placed in a basin (I wash them not in the washing machine) and washed, saving water and detergent.
These are well-made products, like all K&F products I've tried so far.