When set to a number, the tag list switches to a summarized display once the number of selected items reaches or exceeds that threshold. The first summarizeAfter items are rendered as individual tags, and the remaining items are collapsed into a single overflow chip showing the count (e.g. "+5 item(s) selected"). Set summarizeAfter to null to render all selected items as individual tags unless tagMode is set to "single".

Example - summarize after 3 selections

<select id="multiselect" multiple="multiple">
    <option>Item1</option>
    <option>Item2</option>
    <option>Item3</option>
    <option>Item4</option>
    <option>Item5</option>
</select>
<script>
$("#multiselect").kendoMultiSelect({
    summarizeAfter: 3
});
</script>