Mice whose coating is very pleasant to the touch. Adaptation very easy and comfortable grip. I think soon find a real benefit with its use in relation to my carpal tunnel problem. Note that I ordered at the same time another wireless ergonomic vertical mouse brand Anker (Anker vertical ergonomic optical mouse 2, 4 GHz Wireless for Windows and Mac OS, USB, 800/1200/1600 DPI, 5 buttons - Black) at a price of 17.99 euros. It is similar in all respects thereto. It costs 6 euros more and not including batteries while the latter, much cheaper, is accompanied by two batteries. Be careful when searching for this kind of product. As for my purchase, I am quite satisfied.