PowerPact™ R-frame circuit breakers can be used with a variety of internal and external accessories to increase application versatility and meet the demands of modern electrical distribution systems. circuit breaker internal accessories are available either factory installed or field installable. They can be installed in accessory compartments behind the circuit breaker accessory cover. This accessory certified to UL, IEC, CSA, NEMA, NMX, UTE, VDE, BS, CEI, UNE, CCC, W-C Standards.