Basic customs duty cap for specified tariff headings limits payable import duty through targeted exemption at assessment. Prescribes an effective cap on the basic customs duty for imports under Heading Nos. 52.04 to 52.07 by exempting that portion of the duty in the First Schedule to the Customs Tariff Act which exceeds the duty calculated at the specified ad valorem rate, exercising the Government's statutory power and invoking public interest grounds.