The Siemens 5SU9356-1KN32 is a SENTRON RCD-operated circuit breaker — an RCBO that combines overcurrent protection and residual current detection in a single 36 mm wide, 2-pole (1P+N) package.
At 40 °C it derates to 30.4 A, at 45 °C to 29.76 A, at 50 °C to 28.8 A, and at 55 °C to 27.84 A.
Accepts solid or stranded conductors from 0.75 mm² up to 35 mm² — covers everything from a 1.5 mm² lighting circuit to a 10 mm² feeder. Supply can enter from either top or bottom, which simplifies busbar routing in a crowded panel.