CBP looks at whether the article can actually perform the function it represents. Relevant evidence includes design specifications showing the article lacks operational components (e.g., non-functional circuitry, solid-cast interiors, or materials too fragile for real use), manufacturer documentation describing it as a display or training model, and catalog listings that distinguish it from working instruments. A binding ruling request is advisable for borderline articles.

No. The heading requires that the article be unsuitable for other uses by design, not merely that it is used for demonstration in practice. A fully functional oscilloscope or spectrometer used in a classroom remains classified under its functional heading. Only articles that cannot perform the depicted function — because of how they are constructed — belong here.