GPS receivers used primarily as radio navigational aids are generally classified within this SITC group, though at the HTS level they occupy specific subheadings distinct from active radar transmitters. The key classification factor is whether the device is primarily a navigation instrument or a data-processing device that incidentally uses GPS — a distinction that can affect both the duty rate and Section 301 applicability.

Radar apparatus may require FCC equipment authorization for any radio-frequency emitting components, and certain high-performance or dual-use radar systems may be subject to export controls in the country of origin, requiring the foreign supplier to obtain export licenses. On the US import side, defense-related radar equipment may trigger review under national security or end-use-certificate requirements. Importers should conduct an export-control classification review in coordination with their customs broker before shipment.