Schut is a very old company that has been making paper since 1618.
The watercolour paper they produce is called the Schut Terschelling. They use acid free white woodfree cellulose watercolour paper.
The blocks are available in near the usual watercolour paper sizes, plus-minus half to quarter inch. The one I have is 9.5 by 11.75 inch. More common sizes from other brands are 9 by 12 inches.
It doesn't say it's cold press so I guess it's considered rough. It's so rough I won't recommend using pen on it because you won't be able to get a straight line without the nip slipping into the tiny paper grooves. So this is strictly for watercolour, not for mixed media. If you're using a felt tip pen, I'm sure the tip will be worn with just a few drawings.
The quality of the paper is very high. It's really durable. Even when wet, you can brush over it multiple times without the paper fiber appearing. Just for comparison, the Daler Rowney Aquafine blocks takes less than a handful of swipes across the wet surface and paper starts coming out.