items.width String|Number

Determines the width of the item. Valid only for the spacer items. Numeric values are treated as pixels.

Example - set the width for an item

<div id="appbar"></div>
<script>
$("#appbar").kendoAppBar({
    items: [
        {
            type: "contentItem",
            template: "<span><input /><span>"
        },
        {
            type: "spacer",
            width: 60
        },
        {
            type: "contentItem",
            template: "<h1>This is just a text</h1>"
        },
    ]
});
</script>