The Siemens 5SJ4116-8HG40 is a SENTRON 5SJ4-series miniature circuit breaker (MCB) — a 1-pole, 16 A thermal-magnetic device for branch-circuit protection in final distribution panels.
Above 40 °C the curve steps down: 15.5 A at 45 °C, 15 A at 50 °C, 14.5 A at 55 °C, and 14.1 A at 60 °C. DC rating is limited to 60 V maximum — this is an AC-optimized breaker. For DC branch circuits above 60 V you need a different pole configuration or a DC-rated series. Vibration resistance is specified at 50 m/s² over 25–150 Hz and 60 m/s² at 35 Hz (4-second dwell) — it holds up on a machine frame or near a motor without nuisance tripping from vibration.
The 18 mm width (1 MW) means it fits a standard 18 mm-per-pole grid; you can pack multiple poles side by side without odd spacing.
The part is sealable, halogen-free, and silicon-free — useful for food/beverage or clean-room panels where outgassing or contamination must be controlled.