rangeslider.js

$('input[type="range"]').val(10).change();

<input type="range" min="10" max="1000" step="10" value="300">

<script src="jquery.min.js"></script>
<script src="rangeslider.min.js"></script>
<script>
    // Initialize a new plugin instance for all
    // e.g. $('input[type="range"]') elements.
    $('input[type="range"]').rangeslider();

    // Destroy all plugin instances created from the
    // e.g. $('input[type="range"]') elements.
    $('input[type="range"]').rangeslider('destroy');

    // Update all rangeslider instances for all
    // e.g. $('input[type="range"]') elements.
    // Usefull if you changed some attributes e.g. `min` or `max` etc.
    $('input[type="range"]').rangeslider('update', true);
</script>

$('input[type="range"]').rangeslider({

    // Feature detection the default is `true`.
    // Set this to `false` if you want to use
    // the polyfill also in Browsers which support
    // the native <input type="range"> element.
    polyfill: true,

    // Default CSS classes
    rangeClass: 'rangeslider',
    fillClass: 'rangeslider__fill',
    handleClass: 'rangeslider__handle',

    // Callback function
    onInit: function() {},

    // Callback function
    onSlide: function(position, value) {},

    // Callback function
    onSlideEnd: function(position, value) {}
});