godot/editor/icons/GuiSliderGrabberHl.svg

<svg xmlns="http://www.w3.org/2000/svg" width="16" height="16"><circle cx="8" cy="8" r="3" fill="#fff" fill-opacity=".9"/><circle cx="8" cy="8" r="6" fill="none" stroke="#e0e0e0" stroke-width="2"/></svg>