I think that gets to the heart of one of the problems in the current system, which is that Class 2 is hilariously broad and the distinction between Class 2 and

I think that gets to the heart of one of the problems in the current system, which is that Class 2 is hilariously broad and the distinction between Class 2 and Class 3 is also little odd... For example, I actually had no idea that metal in plastic hip implants were Class 2. I think the fact that metal in plastic hip implants are Class 2, but metal on metal were shifted to Class 3 points to something being really off in how the system is implemented. Like I understand that metal in plastic has a long history of use and that in practice that means that they likely have lower risk (in the sense that there are probably less unknown unknowns and known unknowns). But it still feels a little weird, since it doesn't automatically reduce the risk of any specific product/implementation. (For context, compression socks designed to prevent blood pooling in the legs are also Class 2... but all other medical compression socks are Class 1).