Proximity switches and photoelectric sensors that primarily function as detection or sensing devices — rather than as direct-circuit switching apparatus — may classify under instrument or sensor headings rather than here. The classification turns on whether the device's essential character is switching or sensing. Importers of smart or electronic switching devices should review the classification carefully and consider a binding ruling.

Not automatically. The NES qualifier applies within the context of the broader heading structure — a switch must first be confirmed as electrical apparatus for switching circuits at or below 1,000 V, and then verified as not more specifically classifiable under fuse, circuit-breaker, relay, or other enumerated headings. Residual classification here is the result of a deliberate elimination process, not a default.