LA3500 3P 600V 500A Molded Case Circuit Breaker, is now obsolete. This is a factory frame includes 3 lugs and thermal unit/Trip unit. AB-Deion LA Circuit Breakers by Westinghouse now owned by Eaton / Cutler-Hammer Corp. Shunt trips and Auxiliary are available for field installation, however an experienced tech is required. Specify Trip unit desired and specific lug requirements.