The Braille Pattern Dots-1267 symbol (⡣). Copy and paste it, or use its Unicode, HTML, and CSS codes.
More from Braille.
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+2863 (decimal 10339).
Use ⡣ in HTML to render ⡣ on a web page.
On Windows you can type it with Alt+10339 (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.