The Siemens 5SJ6515-7 is a SENTRON 5SJ6 miniature circuit breaker (MCB) with 1P+N poles, meaning it switches and protects both the line and neutral in a single-width module. The C tripping characteristic means it handles inrush currents 5–10× the rated value — typical for motor starters, small transformers, and lighting ballasts — before the magnetic trip fires. At 1.6 A rated, it protects a branch circuit drawing up to that continuous load; the 6 kA breaking capacity per EN 60898 tells you it can safely interrupt a fault current up to that level without welding contacts or cascading upstream. That 6 kA rating also holds per IEC 60947-2, so it's accepted in both residential and light industrial panels.
The 2 width units mean it occupies two 18 mm slots on the rail. Terminal accepts solid or stranded conductors from 0.75 mm² up to 25 mm², so it handles both small control wiring and larger branch-circuit feeds.