Goods can be temporarily imported for, for example, demonstration purposes. If such a product is liable to import duties, a temporary import permit can be obtained. The product can then enter the EU free of import duties, provided that it is not used for production purposes and that it leaves the EU again within a certain time. Such a permit can be granted for a period of up to three years.
The opposite of this is a temporary export permit, for which at re-importing no import duties are due, provided that it can be demonstrated that the goods were exported from the EU first.