The base for plug-in molded case circuit breakers Tmax XT4 with rated currents up to 250 A is available in 3- or 4-pole versions. The Tmax XT4 can be equipped with both thermomagnetic releases for the protection of direct/alternating current networks and with electronic releases for the protection of alternating current networks. The series is also suitable for use in communication systems and 400 Hz systems. The Tmax XT4 molded case circuit breakers are available in a derived version as load-break switches. The Ekip range of electronic overcurrent releases completes the range. Ekip is an interchangeable, microprocessor-controlled release for extreme reliability and precision, which signals operation and protection functions via LEDs. An Ekip Com communication module can be integrated into the Tmax XT4 without taking up any space. Other accessories are available.