5501.30.00.10 - Containing 92 percent or more by weight of acrylonitrile units with filaments numbering fewer than 70,000 (+/-2000) with filament diameter 1.59 decitex (plus or minus 0.027) or less, or in a separable tow construction capable of being separated into tows of 70,000 (+/-2000) or fewer with filament diameter 1.59 decitex (plus or minus 0.027) or less.

This HTS category, 5501.30.00.10, specifically classifies synthetic filament tow composed of acrylonitrile units. The defining characteristics are a high concentration of acrylonitrile (92% or more by weight) and specific filament counts and diameters. This includes tows with fewer than 70,000 filaments, each measuring 1.59 decitex or less, or tows designed to be separable into such smaller tows. These are essentially the raw, continuous thread forms of acrylic or modacrylic fibers before they are cut into staple fibers.

This category is distinguished from its sibling, 5501.30.00.90, which covers "Other" acrylic or modacrylic synthetic filament tow. Therefore, goods classified under 5501.30.00.10 must meet the precise filament number and diameter specifications outlined, whereas 5501.30.00.90 would encompass acrylic or modacrylic filament tow that does not meet these specific technical criteria. This level of detail is crucial for accurate customs declaration, ensuring that the correct tariff rate is applied based on the precise physical attributes of the filament tow.

As this is a leaf node within the HTS, there are no further subcategories to introduce. The classification concludes at this level, with specific product details differentiating it from other potential acrylic or modacrylic filament tow classifications. The emphasis remains on the precise technical specifications related to filament count and diameter as the primary determining factors for inclusion in this specific tariff line.