public function Field($properties = array())
    {
        $options = array();

        foreach ($this->getOptions()->filter('Selected', true) as $option) {
            $options[] = $option->Title;
        }

        $field = ReadonlyField::create($this->name . '_Readonly', $this->title);

        $field->setForm($this->form);
        $field->setValue(implode(', ', $options));
        return $field->Field();
    }