Definition - What does Specific Tax mean?
Specific tax is one that is valued on the weight of an item and not on its resale value. In this way, the tax will not change based on the price of the goods because it is wholly dependent upon the weight that is sold.
Justipedia explains Specific Tax
Excise tax is the most common form of specific tax, and according to the IRS, it's usually already included in a product's price.