See https://en.m.wikipedia.org/wiki/Emergency_oxygen_system for details on the two types of systems used (not an expert, just duck-ducked it out of curiousity). Yes - there is (sometimes) an oxygen candle above each seat. Does that make it a consumer product? I'm not sure and no opinion on that aspect, I mainly included the link for those interested in how they work. To coin a phrase 'Now I know'.