How to change ToolStripEx image size in WinForms RibbonControlAdv?

private void button1_Click(object sender, EventArgs e)
{
    //To Disable Auto Size and Image Scaling
    this.toolStripButton1.AutoSize = false;
    this.toolStripButton1.ImageScaling = ToolStripItemImageScaling.None;
    //To Set user defined Size
    this.toolStripButton1.Size = new Size(35, 35);
}

Private Sub button1_Click(sender As Object, e As EventArgs)
    ‘ To Disable Auto Size and Image Scaling
    Me.toolStripButton1.AutoSize = False
    Me.toolStripButton1.ImageScaling = ToolStripItemImageScaling.None
    ‘ To Set user defined Size
    Me.toolStripButton1.Size = New Size(35, 35)
End Sub