CPV code 45212290 designates Repair and maintenance work in connection with sports facilities in the Common Procurement Vocabulary (CPV 2008), the EU classification used to describe the subject of public contracts.
45212290 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 45212200 (Construction work for sports facilities).