Iron or steel (o/than stainless), doors, windows and their frames, and thresholds for doors
When countries agree to open their markets for goods or services, they “bind” their commitments. For goods, these bindings amount to ceilings on customs tariff rates.
MFN duty rate
Every time a country lowers a trade barrier or opens up a market, it has to do so for the same goods or services from all its trading partners.
Special tariff preference programs