legend.focusHighlight.border.width Number (default: 2)

The width of the focus highlight border in pixels.

Example - set the chart legend focus highlight border width

<div id="chart"></div>
<script>
$("#chart").kendoChart({
  legend: {
    focusHighlight: {
      border: {
        width: 3
      }
    }
  },
  series: [
    { type: "donut",  data: [3, 4] }
  ]
});
</script>