Spotted by Notebookcheck.net, and leaked by the European Union Intellectual Property Office (EUIPO), the pictures show that Logitech is mostly keeping the design of the MX Master 3 and the MX Master 3S. The biggest update is the third button on the side, as well as a larger cutout on the side. The LED is now moved below the scrolling wheel and the smooth scroll button.

It is left to be seen if Logitech has addressed the major drawback to the MX Master 3S, which was the low-quality materials.

Hopefully, we'll see an official announcement soon.