An unfilled warranty booklet alone is not a reliable indication of a counterfeit. More reliable is the packaging: with many known counterfeits, the case is fitted with a metal clip on the bottom and only covered with a cloth, while original boxes appear more solid. Older original boxes were lined with black satin cloth and not with foam, which does not automatically point to a counterfeit. Collectors confirm that a solid, high-quality finished box is a good authenticity feature.