9902.12.45 - Backpacks with outer surface of 230 decitex fabric of nylon and with laminated polyester knitted backing inner surface; such backpacks each weighing 0.85 kg but not over 1 kg, measuring 0.018 m3 but not over 0.022 m3 in volume; valued $14 or more but not over $21 each; the foregoing each presented with a detachable front pouch having its own shoulder strap (provided for in subheading 4202.92.31)

This HTS category, 9902.12.45, is specifically designated for a particular type of backpack. The defining characteristics include an outer surface made of 230 decitex nylon fabric, a laminated polyester knitted backing on the inner surface, and specific weight and volume parameters (0.85 kg to 1 kg, and 0.018 m³ to 0.022 m³ respectively). Additionally, these backpacks must have a value between $14 and $21 each. A crucial element for classification under this heading is that each backpack is presented with a detachable front pouch, which itself includes a shoulder strap and is provided for under subheading 4202.92.31. This detailed set of physical and value-based criteria ensures a very narrow scope for this classification.

As this is a leaf node within Chapter 99, which deals with temporary legislation and special provisions, there are no direct subcategories to differentiate from. However, it's important to understand that classifications within Chapter 99 are typically temporary or subject to specific trade agreements or policy actions, and therefore do not have the same structure of permanent, hierarchical subdivisions as found in the earlier chapters of the HTS. The parent context of Section XXII reinforces this, indicating that this classification falls under special rules and modifications rather than standard product categorization.

The primary function of this classification is to track and potentially impose specific duties or restrictions on these precisely defined backpacks. The detailed description ensures that only those meeting all stipulated material, dimensional, weight, value, and accessory requirements will be classified here. Any variations in material composition, weight, volume, value, or the absence of the specified detachable pouch would necessitate classification under a different HTS code, likely within Chapter 42 which covers articles of leather, saddlery, travel goods, handbags and similar containers, or potentially under other temporary provisions if applicable.