Fiber optic cable transmits signals as light pulses through glass or plastic strands and is classified separately from copper-conductor wire in both NAICS (335921 vs. 335929) and HTS frameworks. The distinction matters for tariff treatment, antidumping order applicability, and Buy America compliance in federally funded infrastructure projects.

Beyond standard customs entry requirements, insulated wire and cable imports may be subject to Section 301 tariffs if sourced from China, and certain products must meet UL or NEC standards for use in US construction. Antidumping and countervailing duty orders have historically covered specific wire and cable products from multiple countries, so checking the USITC and Commerce Department remedy databases before sourcing is essential.