RemixIconEx.Device.mouse

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

mouse(icon_css_class \\ "icon")

iex> Elixir.RemixIconEx.Device.mouse()
<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24" class="icon">
  <path d="M11.141 4c-1.582 0-2.387.169-3.128.565a3.453 3.453 0 0 0-1.448 1.448C6.169 6.753 6 7.559 6 9.14v5.718c0 1.582.169 2.387.565 3.128.337.63.818 1.111 1.448 1.448.74.396 1.546.565 3.128.565h1.718c1.582 0 2.387-.169 3.128-.565a3.453 3.453 0 0 0 1.448-1.448c.396-.74.565-1.546.565-3.128V9.14c0-1.582-.169-2.387-.565-3.128a3.453 3.453 0 0 0-1.448-1.448C15.247 4.169 14.441 4 12.86 4H11.14zm0-2h1.718c2.014 0 3.094.278 4.072.801a5.452 5.452 0 0 1 2.268 2.268c.523.978.801 2.058.801 4.072v5.718c0 2.014-.278 3.094-.801 4.072a5.452 5.452 0 0 1-2.268 2.268c-.978.523-2.058.801-4.072.801H11.14c-2.014 0-3.094-.278-4.072-.801a5.452 5.452 0 0 1-2.268-2.268C4.278 17.953 4 16.873 4 14.859V9.14c0-2.014.278-3.094.801-4.072A5.452 5.452 0 0 1 7.07 2.801C8.047 2.278 9.127 2 11.141 2zM11 6h2v5h-2V6z" />
</svg>

example usage

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