dropDownWidth String|Number

The width of the dropdown. Numeric values are treated as pixels.

Example - set the dropdown width as a string

<input id="multicolumncombobox" />
<script>
$("#multicolumncombobox").kendoMultiColumnComboBox({
  dropDownWidth: "600px",
  dataSource: [
    { Name: "Parent1", Id: 1 },
    { Name: "Parent2", Id: 2 }
  ],
  dataTextField: "Name",
  dataValueField: "Id",
  columns: [
    { field: "Name" },
    { field: "Id" }
  ]
});
</script>

Example - set the dropdown width as a number

<input id="multicolumncombobox" />
<script>
$("#multicolumncombobox").kendoMultiColumnComboBox({
  dropDownWidth: 600,
  dataSource: [
    { Name: "Parent1", Id: 1 },
    { Name: "Parent2", Id: 2 }
  ],
  dataTextField: "Name",
  dataValueField: "Id",
  columns: [
    { field: "Name" },
    { field: "Id" }
  ]
});
</script>