CPV code 42514200 designates Electrostatic air and gas cleaners in the Common Procurement Vocabulary (CPV 2008), the EU classification used to describe the subject of public contracts.
42514200 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 42514000 (Machinery and apparatus for filtering or purifying gases).