CBP uses transaction value as the primary method, but for precious-metal commodities, the declared price must reflect the actual price paid or payable at the time of sale. Importers often support their entry with London Platinum and Palladium Market (LPPM) price records for the relevant date, assay certificates confirming metal content and weight, and purchase contracts. If transaction value cannot be established, CBP may resort to deductive or computed value methods.

The defining characteristic is the specific physical form — woven wire cloth or grill — combined with a catalytic function. Platinum articles in other forms (foil, powder, sponge, rods) or serving non-catalytic purposes classify under different headings. Importers should ensure that technical specifications confirming the woven mesh construction and the intended catalytic application accompany the entry documentation to support classification here.