The Siemens 5SN6106-8CN is a SENTRON 5SN6 series miniature circuit breaker, 1-pole, with a D tripping characteristic, rated 6 A at 400 V AC. Its 6 kA breaking capacity per EN 60898 covers standard distribution board fault levels in residential and light commercial panels. The D-curve (10–20× In) is the key spec here — it's sized for loads with high inrush, like small motors, transformers, or switching power supplies, where a B or C curve would nuisance-trip on startup.
Snaps onto standard DIN rail (EN 60715) in one width unit (18 mm). Terminal accepts 0.75 to 25 mm² conductor, solid or stranded. Mounting position is unrestricted, and the 70 mm installation depth leaves room for wiring behind the panel. IP20 with conductors connected — fine inside a closed distribution board, not for wet or dusty environments.