The Square D C1200-20HDG is a 1-pole thermal-magnetic equipment protector from the QO-EPD family, rated 15 A at 120 VAC 50/60 Hz with a 10 kA interrupting capacity. It plugs into QO loadcenters, NQOD panelboards, and OEM interiors or SPEED-D switchboard distribution panels. A built-in auxiliary switch (1NO, 5 A at 120 VAC) is included for remote status indication.
The 15 A continuous rating and 10 kA interrupting rating (SCCR) define the breaker's fault-clearing capability at 120 VAC. The 30 mA ground-fault trip sensitivity (listed as trip sensitivity) makes this a GFCI-type equipment protector — it will trip on leakage to ground, not just overload or short. That matters if the circuit serves wet or outdoor equipment where personnel protection is required. Terminal pressure plates accept 14–8 AWG copper or 12–8 AWG aluminum, so it handles standard branch-circuit wiring without adapters.