CPV code 33157000 designates Gas-therapy and respiratory devices in the Common Procurement Vocabulary (CPV 2008), the EU classification used to describe the subject of public contracts.
33157000 sits under 33150000 (Radiotherapy, mechanotherapy, electrotherapy and physical therapy devices) and groups 7 more specific sub-codes. When classifying a tender, choose the narrowest code that still covers the full subject of the contract.