Temporary exemption from duty can be granted for goods intended for public displays at exhibitions and fairs, commercial samples, and professional tools and equipment. If the goods are put to unauthorized use or are not exported within the prescribed time they must go through normal customs clearance and become liable for relevant duties and taxes. In Finland, the ATA-Carnet, the international customs documentation for temporary duty-free admission, is issued by the Central Chamber of Commerce. ATA-Carnets are frequently used for temporary imports, e.g. samples, exhibition materials, and professional equipment (laptop computers, software), and are valid for one year.