Radical 13
Radical 13 or radical down box, meaning upside-down box or wide, is one of 23 of the 214 Kangxi radicals that are composed of 2 strokes.
In the Kangxi Dictionary, there are 50 characters to be found under this radical.
冂 is also the 10th indexing component in the Table of Indexing Chinese Character Components predominantly adopted by Simplified Chinese dictionaries published in mainland China.