A stylus probe designed and sold specifically for use with a coordinate measuring machine (CMM) is classifiable as a part of a measuring instrument under this heading, provided it has no practical utility outside CMM applications. The dedicated-use criterion is met when the probe's geometry, thread specification, and material are matched to a specific CMM brand or platform. Technical datasheets and the manufacturer's parts catalog are the standard supporting documents for this classification.

When a component is suitable for use with goods of two or more headings, classification follows the General Rules of Interpretation — specifically GRI 3, which directs classification under the heading that provides the most specific description, or if equally specific, the heading for the article to which the component gives its essential character. A lens marketed and sold primarily as a profile projector replacement part would generally be classified here; a lens sold as a general optical component would likely fall under optical elements headings. Importers with genuinely dual-use components should consider requesting a CBP binding ruling.