Customs duty cap for Chapter 45 goods set by exemption notification, limiting duty to a prescribed ad valorem ceiling. Exempts goods under Chapter 45 of the First Schedule to the Customs Tariff Act, 1975 from customs duty insofar as such duty exceeds 55% ad valorem, by Notification No. 61/90-Cus dated 20-3-1990, issued under the statutory powers conferred by the Customs Act, 1962.