This Tariff Concession Order declares that a narrowly described type of gear set (double-enveloping worm gear sets comprising cone gears and worm wheels, tariff classification 8483.40.90) is covered by item 50 of Part III, Schedule 4 to the Customs Tariff Act 1995 from 11 November 2005 until revoked. It affects importers and customs administration by changing the tariff treatment for those specific goods, which alters import costs and creates a compliance requirement to show the goods match the description.