The Siemens 5SU1354-1KK06 is a SENTRON RCBO — a combined residual-current circuit breaker with overcurrent protection in a single 2-module-width package (36 mm wide, 77 mm deep, 90 mm tall). It protects a single-phase final subcircuit: one pole switched and protected, neutral switched but not protected (1P+N design).
That 35 kA figure gives real SCCR headroom downstream of a larger upstream breaker — useful when coordinating with a 63 A or 100 A feeder in a Type 2 coordination study.
Temperature derating — don't ignore it
At 40 °C it derates to 5.7 A, at 50 °C to 5.4 A, at 60 °C to 5.1 A, and at 70 °C to 4.62 A. If this RCBO lives in a crowded DIN rail enclosure near transformers or drives, size the load to the derated current at the expected internal temperature — not the 30 °C nameplate figure.
Mounts in any position on DIN rail. IP20 with conductors connected and board installed.