Mechanically, this Tariff Concession Order (TCO 1112409) declares that thermoplastic pressure‑testing hoses with an inside diameter not greater than 4 mm (tariff code 3917.31.90) are to be treated as goods to which Item 50 in Part III of Schedule 4 to the Customs Tariff Act 1995 applies, effective 13 April 2011 until revoked (see s.269P; ss.269SC/269SD). Importers of these hoses and the customs administration are directly affected because the order changes the tariff treatment and therefore import duty liability, compliance steps and administrative processing.