CPV code 31711520 designates Parts of electrical resistors, rheostats and potentiometers in the Common Procurement Vocabulary (CPV 2008), the EU classification used to describe the subject of public contracts.
31711520 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 31711500 (Parts of electronic assemblies).