9001.90 - Other:

This HTS category, "Other," within heading 9001 encompasses optical elements that are not specifically enumerated in the preceding subheadings. It is designed to capture various unmounted optical components that are not optical fibers, polarizing material, contact lenses, or spectacle lenses. The critical defining factor for inclusion here is that the item must be an optical element, meaning it is designed to refract, reflect, or otherwise manipulate light, and it is not otherwise specified.

Unlike its sibling categories, 9001.10 (optical fibers), 9001.20 (polarizing material), 9001.30 (contact lenses), 9001.40 (glass spectacle lenses), and 9001.50 (other spectacle lenses), this residual category applies to optical elements that do not fit into these more specialized classifications. For instance, while spectacle lenses are covered under 9001.40 and 9001.50, this "Other" category would not apply to them. Similarly, items like lenses, prisms, and mirrors, when unmounted and not falling under other specific headings, will be classified here.

The subcategories within 9001.90 provide a more granular breakdown for common types of optical elements. 9001.90.40.00 covers unmounted lenses for general optical applications, 9001.90.50.00 addresses unmounted prisms, and 9001.90.60.00 pertains to unmounted mirrors. The residual "Other" designation within this group signifies items that are optical elements but do not fit neatly into the lens, prism, or mirror classifications, and are not otherwise covered by the parent heading's more specific subheadings.