The Yi Radicals block spans U+A490–U+A4CF, 64 codepoints in Plane 0 (Basic Multilingual Plane). 55 are assigned in Unicode 16.0; the other 9 are reserved for future characters.
All of its characters belong to the Yi script.
By general category: 55 other symbols (So).
The first 50 arrived in Unicode 3.0 (1999); later additions came in 3.2 (5).
55 characters are East Asian Wide or Fullwidth and take two columns in terminals.