9902.12.17 - Camera mounts of plastics, engineered to operate with cameras of subheading 8525.80.40 and facilitate mounting of cameras onto tubes measuring 3.5 to 6.35 cm in diameter, the foregoing incorporating a base capable of rotating the camera 360 degrees on a plane (provided for in subheading 3926.90.99)

This HTS classification, 9902.12.17, specifically designates camera mounts constructed from plastics. These mounts are engineered with a precise functional requirement: to interface with cameras classified under subheading 8525.80.40. A key characteristic of these mounts is their ability to accommodate tubes with diameters ranging from 3.5 to 6.35 cm, facilitating the secure attachment of cameras to such structures. Furthermore, the design incorporates a base mechanism that allows for 360-degree rotational movement of the camera within a single plane. This specific combination of material, intended use with designated cameras, tube size compatibility, and rotational functionality distinguishes it from other general plastic articles or camera accessories.

As a leaf node within Chapter 99, this classification focuses on very specific temporary legislation or modifications. Therefore, it does not have direct "sibling" categories in the traditional sense that would cover broader product groups at the same level within this specific chapter. Instead, its distinction comes from its highly specialized nature. While other categories in Chapter 99 might represent temporary trade agreement provisions or import restrictions, 9902.12.17 carves out a niche for these particular plastic camera mounts by linking them to a specific camera subheading and defining their unique physical and functional attributes for purposes of special classification.