RemixIconEx.System.arrow_drop_down

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

arrow_drop_down(icon_css_class \\ "icon")

iex> Elixir.RemixIconEx.System.arrow_drop_down()
<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24" class="icon">
  <path d="M12 15l-4.243-4.243 1.415-1.414L12 12.172l2.828-2.829 1.415 1.414z" />
</svg>

example usage

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