A complete frame already mounted on its shaft or stick falls under 660320, while individual ribs, stretchers, handles, or other loose fittings are classified under 660390 as parts, trimmings, or accessories. The distinction matters because the two subheadings can carry different duty rates.

Yes. Each imported component must be marked with its country of origin unless it qualifies for a marking exception. When parts from multiple countries are combined domestically, the finished article's origin is determined by the substantial-transformation test, which can affect both marking and any applicable trade-remedy exposure.