Markup: templates/output/04-elements/forms/input/radio.html
<fieldset>
<legend>Treffen Sie ihre Auswahl</legend>
<div class="form-radiogroup ">
<input id="radio1" name="radio1" type="radio" checked="checked"/>
<label for="radio1"><span>Option 1</span></label>
<input id="radio2" name="radio2" type="radio"/>
<label for="radio2"><span>Option 2</span></label>
</div>
</fieldset>
Source:
assets/sass/04-elements/_elements.forms.scss, line 472