Tooltips

There are two ways to assign tooltips to RadToggleButton, namely setting the ToolTipText property of the RadToggleButtonElement, or as in most of the RadControls by using the ToolTipTextNeeded event of RadToggleButton. It is necessary the ShowItemToolTips property to be set to true which is the default value.

Setting the ToolTipText property

this.radToggleButton1.ButtonElement.ToolTipText = "I am a toggle button";

Me.radToggleButton1.ButtonElement.ToolTipText = "I am a toggle button"

Setting tool tips in the ToolTipTextNeeded event

private void RadToggleButton1_ToolTipTextNeeded(object sender, Telerik.WinControls.ToolTipTextNeededEventArgs e)
{
    e.ToolTipText = "Click me";
}

Private Sub RadToggleButton1_ToolTipTextNeeded(sender As Object, e As Telerik.WinControls.ToolTipTextNeededEventArgs)
    e.ToolTipText = "Click me"
End Sub

The ToolTipTextNeeded event has higher priority and overrides the tool tips set in the ToolTipText property.