RemixIconEx.Document.folder_open

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

folder_open(icon_css_class \\ "icon")

iex> Elixir.RemixIconEx.Document.folder_open()
<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24" class="icon">
  <path d="M3 21a1 1 0 0 1-1-1V4a1 1 0 0 1 1-1h7.414l2 2H20a1 1 0 0 1 1 1v3h-2V7h-7.414l-2-2H4v11.998L5.5 11h17l-2.31 9.243a1 1 0 0 1-.97.757H3zm16.938-8H7.062l-1.5 6h12.876l1.5-6z" />
</svg>

example usage

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