https://wccftech.com/s-pen-pro-specifications-leak-closer-to-the-launch/

Canceling the Galaxy Note 21 for this year and launching the Galaxy S21 Ultra with S Pen support was a gamble for Samsung that paid off, and while it is not a full integration, it still is a nice thing to see. With that said, the standard S Pen that you can buy for your Galaxy S21 Ultra does not support Bluetooth LE connectivity, and this means that it lacks some of the features compared to the older renditions of the S Pen. Samsung did announce the S Pen Pro that would solve that issue and have a larger body. However, they did not reveal the full feature set or the specifications, for that matter.

According to a tip from Chun, we now have some information on the S Pen Pro and what it will be bringing to the table.