The AP12-1-51-302 is a two-pole, series configuration magnetic circuit protector designed for reliable overcurrent protection. This fully sealed unit features a nominal current rating of 3.000 amperes, hook terminals, and is configured for DC circuits with a short time delay. Its hydraulic-magnetic design ensures the trip current is stable over a wide temperature range, and a single toggle handle actuates both poles, with an overload in either circuit tripping both simultaneously. The protector is trip-free, meaning it will open the circuit during an overload even if the handle is held in the ON position, making it suitable for critical applications like communication systems, aircraft instrumentation, radar, and power supplies.