This Order declares that specific goods classified at tariff item 8417.90.00 — “parts, walking beam furnace, being recuperator tubes” — are eligible for the tariff treatment set out in Part III, Schedule 4 item 50. It takes effect from 20 April 2005 and continues until revoked under ss 269SC–269SD of the Customs Act 1901 (made under s 269P). Mechanically, it lets importers treat those parts as falling under the listed Schedule 4 item when clearing customs; importers must correctly classify and claim the concession, and customs applies or withdraws it per the revocation rules.