CPV code 38515100 designates Polarising microscopes in the Common Procurement Vocabulary (CPV 2008), the EU classification used to describe the subject of public contracts.
38515100 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 38515000 (Fluorescent and polarising microscopes).