Customs duty exemption permits reduced basic duty and waives additional duty on specified non-electronic components, subject to certification and undertaking Exemption relieves specified non-electronic components (Chapters 84, 85, 90, 98, excluding parts containing thermionic valves, transistors, LEDs, electronic micro circuits or capacitors) imported for manufacture of goods covered by the earlier notification from the portion of basic customs duty above a stated ad valorem threshold and from the whole of the additional duty under section 3, subject to certification by an authorised technical officer and an importer undertaking to use the components for the specified purpose and to pay any duty difference on breach.