What the ratings mean for fit
The Siemens 5SY4216-7CC11 is a SENTRON miniature circuit breaker (MCB) in a 2-pole (2P) configuration, rated 16 A at AC with a C tripping characteristic. That C-curve means it trips at 5 to 10 times rated current — designed for moderate inrush loads like small motors, transformers, or lighting banks where you need to ride through the start-up surge without nuisance tripping. The 10 kA breaking capacity at EN 60898 tells you it can safely interrupt a short-circuit fault up to that level; in a panel with higher prospective fault current you'd need to coordinate upstream or step to a higher-rated device.
Temperature derating — the real current you get
The 16 A rating holds at 35 °C ambient. Above that, derate linearly: 15.04 A at 40 °C, 14.54 A at 45 °C, 14.02 A at 50 °C, 13.47 A at 55 °C, and 12.91 A at 60 °C. If your panel runs hot — say 50 °C inside the enclosure — this breaker is effectively a 14 A device. Plan your load accordingly; don't treat the 16 A label as usable at every ambient.