This Tariff Concession Order (declared under s.269P of the Customs Act 1901) treats a narrowly described class of refractory bricks (tuyere zone or bosh, fired, meeting specified SiC, density, porosity, strength and free‑carbon thresholds) as goods to which an item in Part III of Schedule 4 of the Customs Tariff Act 1995 applies, effective 4 October 2006. Mechanically, importers can claim the listed tariff concession for those goods; they must ensure the imported product matches the stated technical description and the order remains in force until formally revoked (ss.269SC/269SD).