9902.17.52 - Emergency lights, of base metal other than of brass, round or elongated in shape, measuring between 6 and 12 cm in height, each containing incandescent lamp, lamp holder, reflector, clear glass lens with drain hole, pressure can and electrical pigtail with connector; the foregoing configured to be mounted to the exterior of an aircraft and designed for illuminating egress paths on or around the aircraft during an emergency evacuation (provided for in subheading 9405.40.60)

This HTS category, 9902.17.52, specifically classifies specialized emergency lights intended for aircraft use. These lights are characterized by their construction from base metal (excluding brass), a round or elongated shape with a height between 6 and 12 cm, and the inclusion of an incandescent lamp, lamp holder, reflector, a clear glass lens with a drain hole, a pressure can, and an electrical pigtail with a connector. Critically, these lights are designed for exterior mounting on an aircraft and are engineered to illuminate egress paths during emergency evacuations. The "provided for in subheading 9405.40.60" notation indicates the underlying classification for these types of lights within the broader HTS structure.

Distinguishing this category from its siblings, which primarily encompass live animals, is straightforward. HTS Chapter 99, and this specific subheading within it, deals with temporary legislative provisions and modifications, often for specific purposes like temporary duty suspensions or restrictions. Unlike the general merchandise classifications found in earlier chapters, 9902.17.52 is a highly specific provision for a particular type of safety equipment with a defined end-use in aviation.

As this is a leaf node within the HTS structure, there are no further subcategories to explore. Classification under 9902.17.52 is determined by meeting all the detailed physical and functional criteria outlined in its description. Importers and exporters must ensure that the emergency lights precisely match the specified materials, dimensions, components, and intended application to correctly utilize this temporary classification provision.