Code point
U+3391
Glyph appearance depends on your fonts.
U+3391
So<square> 006B 0048 007AU+3391 SQUARE KHZ is a Unicode 16.0.0 character in the Other Symbol category. It belongs to the CJK Compatibility block.
Choose the representation you need, then copy its value.
U+3391
13201
㎑
㎑
E3 8E 91
3391
00003391
%E3%8E%91
\u3391
\u3391
\u3391
\3391