9030.90.89.21 - Of articles of subheading 9030.31

This HTS code, 9030.90.89.21, specifically covers parts and accessories pertaining to instruments and apparatus for measuring or checking electrical quantities, as described under subheading 9030.31. Subheading 9030.31 encompasses oscilloscopes and spectrum analyzers. Therefore, this classification would apply to components, fittings, and ancillary items designed for use with these specific types of electrical measuring devices, such as probes, connectors, specialized cables, or internal circuit boards uniquely manufactured for these instruments.

It is crucial to distinguish this category from its sibling entries. For instance, sibling category 9030.90.89.11 pertains to parts for oscilloscopes and spectrum analyzers covered by subheading 9030.20, which are a different set of electrical measuring instruments. Similarly, codes like 9030.90.89.22 and 9030.90.89.23 are designated for parts related to subheadings 9030.32 and 9030.33 respectively, which cover other types of electrical quantity measuring apparatus. The precise designation of 9030.90.89.21 relies on the specific reference to subheading 9030.31, highlighting the direct link between the part and the particular instrument type.

As this is a leaf node within the HTS structure, there are no further subcategories to explore. Therefore, the classification is definitive at this level. When classifying items under 9030.90.89.21, focus on whether the part or accessory is exclusively designed or adapted for use with oscilloscopes or spectrum analyzers falling under subheading 9030.31, ensuring it is not interchangeable with parts for other categories of electrical measuring instruments.