RemixIconEx.Document.contacts_book

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

contacts_book(icon_css_class \\ "icon")

iex> Elixir.RemixIconEx.Document.contacts_book()
<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24" class="icon">
  <path d="M3 2h16.005C20.107 2 21 2.898 21 3.99v16.02c0 1.099-.893 1.99-1.995 1.99H3V2zm4 2H5v16h2V4zm2 16h10V4H9v16zm2-4a3 3 0 0 1 6 0h-6zm3-4a2 2 0 1 1 0-4 2 2 0 0 1 0 4zm8-6h2v4h-2V6zm0 6h2v4h-2v-4z" />
</svg>

example usage

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