Core Viewpoint - The Chinese Ministry of Commerce has determined that U.S. fiber optic manufacturers and exporters are circumventing anti-dumping measures by exporting G.654.C fiber optics to China, which will now be subject to the same anti-dumping duties as G.652 fiber optics starting from September 4, 2025 [1][2] Group 1: Anti-Dumping Measures - The current anti-dumping tax rate for U.S. G.652 fiber optics is between 33.3% and 78.2%, which will now apply to G.654.C fiber optics as well [1] - The Ministry of Commerce initiated an anti-circumvention investigation in March 2025 at the request of domestic companies, marking China's first such investigation [1][2] - The investigation revealed that U.S. exporters were using G.654.C fiber optics to bypass the anti-dumping measures on G.652 fiber optics, undermining the effectiveness of these measures [2] Group 2: Historical Context - The anti-dumping tax on U.S. G.652 fiber optics was first imposed in April 2011 for a period of five years, and it has been extended multiple times since then, with the latest extension announced in April 2023 [2] - The compatibility and substitutability between G.652 and G.654.C fiber optics have been highlighted as a key factor in the circumvention of the existing anti-dumping measures [2]