The Siemens SENTRON 5SL4408-7RC is a 4-pole miniature circuit breaker (MCB) from the 5SL4 series, rated 8 A with a C tripping characteristic and a 10 kA breaking capacity per EN 60898 at 415 V AC.
The 8 A rated current sets the continuous load limit — expect to run it at 80 % (6.4 A) for a comfortable thermal margin. The 415 V AC rating matches three-phase line-to-line voltage in European 230/400 V networks; the maximum operating voltage with multi-phase operation is 440 V.
The 18 mm width per pole means a 4-pole unit occupies four adjacent slots — plan your rail fill accordingly. Terminal screws accept solid or stranded copper from 0.75 mm² up to 25 mm²; tighten to 2.5–3 N·m.