CPV code 09211610 designates Liquids for hydraulic purposes in the Common Procurement Vocabulary (CPV 2008), the EU classification used to describe the subject of public contracts.
09211610 is a leaf code — the most specific level of its branch — so it can be used directly as the main CPV code of a contract notice. If it does not quite fit, check the neighbouring codes under 09211600 (Oils for use in hydraulic systems and other purposes).