I designed this thing for a friend (for educational use) but I designed it in order to be functional. The large ring is Ø 160 mm and the small ring is Ø 120 mm.
Depending on what filament you use, it can be quite flexible. I printed one in PETG and one in ASA. They both work well as far as I have tested.
The plate guard is supposed to be an eating aid, e.g. when eating with one hand.
Concerning food safety: This is all a matter of the printer setup, filament type and how often and how you use the printed part. In general: Any FDM printed part has a raw surface with small holes, where bacteria can grow over time. Just keep that in mind and be responsible with your 3D printed parts.
FormFutura ApolloX (ASA)