toolbar.items.imageUrlString
If set, the ToolBar will render an image with the specified URL in the button.
Example
<div id="fileManager"></div>
<script>
    var baseUrl = "https://demos.telerik.com/service/v2/core/filemanager/";
    $("#fileManager").kendoFileManager({
        toolbar: {
            items: [
                { name: "createFolder", imageUrl: "/path/to/folder-icon.png" }
            ]
        },
        dataSource: {
            transport: {
                read: {
                    method: "POST",
                    url: baseUrl + "Read"
                }
            }
        }
    });
</script>In this article