The Airpax AP series are fully sealed, magnetic circuit protectors designed to combine power switching with accurate and reliable circuit protection. Unlike thermal protectors, the AP maintains a consistent trip current across a wide temperature range. Available in DC, 50/60Hz, or 400Hz versions with various delays, these protectors are suitable for a wide range of applications including communication, navigation, aircraft instrumentation, radar, and power supplies. The 'trip-free' action ensures the circuit won't remain closed during an overload, even with the handle in the ON position. The AP/UP series offers UL recognition and CSA certification, while AP-MIL protectors meet MIL-PRF-39019 standards. Multi-pole configurations allow for complex circuit protection schemes, such as series breakers, shunt configurations, and relay setups.