RemixIconEx.System.checkbox_circle

You're seeing just the function checkbox_circle, go back to RemixIconEx.System module for more information.
Link to this function

checkbox_circle(icon_css_class \\ "icon")

iex> Elixir.RemixIconEx.System.checkbox_circle()
<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24" class="icon">
  <path d="M12 22C6.477 22 2 17.523 2 12S6.477 2 12 2s10 4.477 10 10-4.477 10-10 10zm0-2a8 8 0 1 0 0-16 8 8 0 0 0 0 16zm-.997-4L6.76 11.757l1.414-1.414 2.829 2.829 5.656-5.657 1.415 1.414L11.003 16z" />
</svg>

example usage

svg.icon {
  width: 96;
  height: 96;
}