The Square D GC200B is a ground fault protection relay — a GRD FLT REL as the description puts it — that lives on a DIN rail in the panel. It's not a breaker itself; it's the relay that watches for earth leakage and kicks out a trip or alarm signal when it sees trouble. Rated operational voltage is 120 V AC, and the output current sits at 5 A for normal operation with a 10 A trip/alarm threshold. That 10 A figure is the point where it commits to the alarm or trip action, not a continuous carry rating.
What the earth-leakage sensitivity range means
This relay can be set to trip on earth-leakage currents from 300 mA all the way up to 3000 mA — with stops at 600, 900, 1200, 1500, 1800, 2100, 2400, and 2700 mA along the way. That's a broad adjustable band, which matters when you're trying to coordinate ground-fault protection downstream without nuisance tripping on a motor start or a capacitive load. Pick a lower sensitivity (300 mA) for personnel protection on a wet floor; dial it up toward 3000 mA if you're protecting a feeder where the natural leakage of long cable runs or VFD filters would otherwise false-trip a sensitive setting.