The Box Drawings Down Light and Up Horizontal Heavy symbol (╇). Copy and paste it, or use its Unicode, HTML, and CSS codes.
More from Box Drawing.
The quickest way is to copy ╇ from this page and paste it anywhere. You can also insert it with its Unicode, HTML, or alt code listed above.
╇ is U+2547 (decimal 9543).
Use ╇ in HTML to render ╇ on a web page.
On Windows you can type it with Alt+9543 (hold Alt and enter the number on the numeric keypad).
Yes — copying is completely free and unlimited, and works right in your browser with no sign-up.