RadControls for ASP.NET AJAX You can set the header and pop up width and height of a specified dropdown tool of RadEditor for ASP.NET AJAX:
CopyASPX
<telerik:RadEditor runat="server" OnClientLoad="OnClientLoad" ID="RadEditor1">
<Tools>
<telerik:EditorToolGroup>
<telerik:EditorTool Name="FontName" popupwidth="300px" popupheight="300px" width="300px" />
</telerik:EditorToolGroup>
</Tools>
</telerik:RadEditor>
CopyXML
<tools>
<tool name="FormatBlock" popupheight="250px"/>
<tool name="FontName" popupwidth="300px" />
<tool name="RealFontSize" width="200px" />
</tools>
CopyC#
Telerik.Web.UI.EditorTool tool = RadEditor1.Tools[5].FindTool("FontName");
tool.Attributes["popupwidth"] = "300px";
tool.Attributes["popupheight"] = "300px";
tool.Attributes["width"] = "300px";
CopyVB.NET
Dim tool As Telerik.Web.UI.EditorTool = RadEditor1.Tools(5).FindTool("FontName")
tool.Attributes("popupwidth") = "300px"
tool.Attributes("popupheight") = "300px"
tool.Attributes("width") = "300px"