Square D LE-frame electronic trip molded case circuit breakers provide thermal magnetic protection. Their primary function is automatic opening of a circuit under overload or short circuit conditions or manual opening. They are designed to meet residential, commercial, and industrial requirements to protect electrical systems, equipment, and people. This unit has a Micrologic 3.3S standard trip LSI trip unit. This circuit breaker can be adjusted from 125A to 400A. This device is UL and CSA listed.