If a heating element is identifiable — by design, specification, or marketing — as solely or principally used with a particular appliance type (such as an oven or hair dryer), it may be classified under that appliance's dedicated parts provision rather than the NES parts heading. The NES heading applies when the component serves multiple appliance types or when no more specific parts provision exists. Importers should document the component's intended application and review CBP rulings for similar parts.

US customs law permits importers to declare the transaction value at the first arm's-length sale in the chain of commerce (e.g., the factory-to-middleman price) rather than the middleman-to-importer price, provided the goods were destined for US export at the time of that first sale and the importer can document the earlier transaction. For high-volume parts shipments subject to Section 301 tariffs, the duty savings from first-sale valuation can be material; a licensed customs broker or trade attorney can advise on documentation requirements.