Specific duty:

In the case of some goods, duty is payable on the basis of certain unit, length, weight, volume, etc. For instance, duty payable on cigarettes is on the basis of length. However, this method of levying duty demands frequent revisions in order to increase revenue since while the prices may be increasing, the duty would remain the same quantum when based on length. Since specific duties do not keep pace with inflation, more and more tariff entries are designed based on advalorem duty structure.