The Siemens 5SU1353-7KV10 is an FI/LS protector — a combined residual-current device and miniature circuit breaker (RCBO) in one DIN-rail module. It carries Type A residual-current detection at 30 mA sensitivity, meaning it catches both sinusoidal AC fault currents and pulsating DC fault currents that a basic Type AC device would miss. That matters for circuits with variable-speed drives, switching power supplies, or other electronics that generate pulsed DC leakage. The overcurrent side is a C-curve 10 A single-pole breaker with a 4.5 kA breaking capacity. It's a 1+N-pole device — the line pole is switched and protected, the neutral pole is switched only (no overcurrent protection on neutral). That's standard for single-phase final circuits where neutral isolation is required for safety isolation.
Where it goes and how it fits
The 70 mm depth (from the description) fits typical consumer unit and industrial enclosure depths, but check your enclosure's door clearance if it's a shallow box.