(2) On receipt of a licence issued under subsection (1), an approved enterprise may import plant, equipment, machinery, spare parts, raw materials or components thereof free from customs duty from an area outside the Common Market for the period of relief specified in section 12 or in section 19(3) or 19(4), if the Comptroller of Customs and Excise is satisfied that the plant, equipment, machinery, spare parts, raw materials or components thereof are or were required—
-
(a) for constructing, altering, reconstructing or extending the approved enterprise; or
-
(b) for equipping such an enterprise for the purpose of manufacturing an approved product.