The Schneider Electric GV4LE03S6 is a 3-pole motor circuit breaker from the TeSys GV4 series, rated for 3.5 A continuous current. That 3.5 A is the motor full-load current it protects — pair it with a contactor sized for the same motor FLA. The magnetic-electronic trip unit gives it a magnetic trip window of 21 to 49 A, so it handles inrush without nuisance tripping on a 0.55 kW motor at 400 V. Breaking capacity is the headline here: 120 kA Icu at 240 V AC, 100 kA at 415 V, and still 10 kA at 690 V. That means it can sit upstream of a fault with enough interrupting capacity to clear a bolted short without the upstream feeder breaker having to open — selectivity without a bigger frame. Rated for isolation per IEC 60947-1, so it doubles as a visible disconnect.
The GV4L frame takes a 27 mm connection pitch without spreaders, 35 mm with. That's a standard DIN-rail footprint — snaps onto the rail, no screws. The toggle control and lugs/ring terminals mean a panel builder can land 16 to 95 mm² cable at 9 N·m torque, or 1.5 to 10 mm² at 5 N·m. IP40 front-of-panel protection, IK07 impact rating — it's a panel-mount device, not a washdown unit. The grey RAL 7016 housing is the standard TeSys Deca colour. Operating altitude up to 5000 m means it's fine for high-altitude installations without derating.