This Order (TCO 1038730) declares specific parts of a directional drilling tool (upper/lower hanger and bearing, upper/lower torquer, pressure housing with electronics and sensor chassis, impeller) at tariff heading 8431.43.00 to be eligible for the concessional treatment in Part III, Schedule 4 (item 50). It takes effect 20 Aug 2010 and runs until revoked under ss 269SC or 269SD. Mechanically, the customs delegate decides eligibility; importers receive the Schedule 4 tariff treatment if correctly classified, affecting their tariff liability and requiring accurate matching to the listed description.