I took a couple of mice, the first one came across with a defective surface, and the second one, it seems, already from the new batch had a terribly loud scrolling of the wheel . = returned . Both mice from the sealed boxes were scratched and worn, if you look at them carefully, and the bottom surface is worn like other brands - it feels like it is second-hand, but I think it's so "carefully" they are checked at the factory . The mouse sensor is too strange on a black mat, some kind of execution to set it up, of course, you can get used to everything, but damn it, even on the Logitech M170 it is smoother in my opinion. It's a pity, because the shape of the mouse is very comfortable and the weight is optimal, a quiet, smooth and high-quality wheel would be put here - it would be a great mouse, otherwise it is not worth the money in my opinion .