Code point
U+239C
Glyph appearance depends on your fonts.
U+239C
SmU+239C LEFT PARENTHESIS EXTENSION is a Unicode 16.0.0 character in the Math Symbol category. It belongs to the Miscellaneous Technical block.
Choose the representation you need, then copy its value.
U+239C
9116
⎜
⎜
E2 8E 9C
239C
0000239C
%E2%8E%9C
\u239C
\u239C
\u239C
\239C