This item is an ABB SACE Shunt Opening Release (SOR), part number 1SDA054863R1. It is a specialized accessory designed to enable remote tripping of Molded Case Circuit Breakers (MCCBs) Compatibility: Specifically engineered for use with ABB SACE Tmax series circuit breakers, models T4, T5, and T6 This is a brand new item in original packaging