JSFiddle - React, Tailwind, and code Playground

HTML

<script src="http://code.jquery.com/mobile/1.3.2/jquery.mobile-1.3.2.min.js"></script>
<link rel="stylesheet" href="http://code.jquery.com/mobile/1.3.2/jquery.mobile-1.3.2.min.css">
<label for="slider-vertical">Betriebsstunden pro Jahr</label>
<input type="range" name="slider-vertical" id="slider-vertical" value="1500" step="25" min="0" max="8760" data-show-value="true" data-theme="b" data-popup-enabled="true" data-highlight="true" />
</div>
<div style="float:left; margin-top:31px;">	<a data-role="button" data-inline="true" data-theme="b" id="minus1">-</a>
	<a data-role="button" data-inline="true" data-theme="b" id="plus1">+</a>

</div>

JavaScript

$("#plus1").on("mousedown", function () {
    $('#slider-vertical').val(Number($('#slider-vertical').val())+25)
});