CPV code 50421100 designates Repair and maintenance services of wheelchairs in the Common Procurement Vocabulary (CPV 2008), the EU classification used to describe the subject of public contracts.
50421100 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 50421000 (Repair and maintenance services of medical equipment).