pendalf89\filemanager\Module::getDefaultThumbSize PHP Method

    public static function getDefaultThumbSize()
    {
        return self::$defaultThumbSize;
    }

 /**
  * @param $baseUrl
  * @return string default thumbnail for image
  */
 public function getDefaultUploadThumbUrl($baseUrl = '')
 {
     $size = Module::getDefaultThumbSize();
     $originalFile = pathinfo($this->url);
     $dirname = $originalFile['dirname'];
     $filename = $originalFile['filename'];
     $extension = $originalFile['extension'];
     $width = $size[0];
     $height = $size[1];
     return "{$dirname}/{$filename}-{$width}x{$height}.{$extension}";
 }