The Siemens 5SU1353-1KV10 is a combined residual-current and miniature circuit breaker (RCBO) — an FI/LS protector in Siemens' nomenclature. It's a 1+N-pole unit with a Type AC residual-current trip set at 30 mA and an overcurrent characteristic of C-curve at 10 A, with a 4.5 kA short-circuit breaking capacity. The D=70 mm dimension matches the standard Siemens FI/LS housing depth for panel integration on DIN rail.
For circuits with rectified loads, a Type A or Type F device would be required. The 30 mA sensitivity covers personnel protection (indirect contact). The C-curve overcurrent characteristic suits inductive loads like small motor circuits and lighting banks where inrush is moderate.