The Supplemental Arrows-B block spans U+2900–U+297F, 128 codepoints in Plane 0 (Basic Multilingual Plane). Every one of them is assigned in Unicode 16.0.
All of its characters have the script value Common: they are shared across writing systems rather than tied to one.
By general category: 128 math symbols (Sm).
The first 128 arrived in Unicode 3.2 (2002).
2 of its characters are emoji, all with text presentation by default (add U+FE0F for the emoji style). See emoji.