The Siemens 5SJ4304-8HG41 is a SENTRON 5SJ4 series miniature circuit breaker — 3-pole, D-curve, rated 4 A at AC and up to 60 V DC. That 4 A rating holds at 30 °C and 40 °C; it derates to 3.6 A at 60 °C ambient. Snaps onto standard DIN rail, any mounting position. The 70 mm depth and 54 mm width (3 modular units) match the standard SENTRON footprint — drops into an existing panel layout without re-drilling or re-spacing.
The 60 V DC maximum rating covers control-circuit and small DC motor applications — not a 125 VDC telecom breaker. The 3-pole block handles three-phase AC loads up to 4 A per phase. Overvoltage category 3 and pollution degree 3 mean it's rated for fixed-installation panels in industrial environments, not just residential. Sealable (yes) lets you lock the handle position for lockout/tagout compliance.
Vibration resistance tested to 50 m/s² at 25–150 Hz and 60 m/s² at 35 Hz (4 sec) — survives the shake of a machine-mounted panel. Designation per IEC 81346-2 and DIN EN 61346-2: F (protective device). Suitability for operation listed as mechanical engineering / industry — the standard target for this class.