CSS selector for custom Qt class

I created a "Slider" subclass of QWidget and would like to be able to style it with Qt's stylesheets. Is there a way to declare the widget to Qt application so that this setting in the application stylesheet is applied to all sliders ?

Slider { background-color:blue; }

Or if this is not possible, can I use a class like this ?

QWidget.slider { background-color:blue; }