selected.js

Select multiple + .selected-light

<link type="text/css" href="selected.min.css" rel="stylesheet" />
<link type="text/css" href="selected-light.min.css" rel="stylesheet" />
<script type="text/javascript" src="selected.min.js"></script>

<select multiple class="selected selected-light">
    <option>Option one</option>
    <option>Option two</option>
    ...
</select>

Select single + .selected-light

<link type="text/css" href="selected.min.css" rel="stylesheet" />
<link type="text/css" href="selected-light.min.css" rel="stylesheet" />
<script type="text/javascript" src="selected.min.js"></script>

<select class="selected selected-light">
    <option>Option one</option>
    <option>Option two</option>
    ...
</select>

Select multiple + basic styles

<link type="text/css" href="selected.min.css" rel="stylesheet" />
<script type="text/javascript" src="selected.min.js"></script>

<select multiple class="selected">
    <option>Option one</option>
    <option>Option two</option>
    ...
</select>

Select single + basic styles

<link type="text/css" href="selected.min.css" rel="stylesheet" />
<script type="text/javascript" src="selected.min.js"></script>

<select class="selected">
    <option>Option one</option>
    <option>Option two</option>
    ...
</select>