Exemption of excise for electronic hardware park units permits limited domestic sale, subject to duty measured against customs equivalents. All excisable goods manufactured in an Electronic Hardware Technology Park Unit under the hundred per cent export oriented scheme and allowed to be sold in India up to a limited proportion of total production are exempted from so much of excise duty as is in excess of an amount calculated by reference to customs duties on like imported goods; a minimum aggregate duty floor applies (being either an ad valorem duty floor or the excise duty specified in the tariff schedule, whichever is higher), with nil rated customs goods excluded and apportionment of the ad valorem amount among customs duties.