Switching duty rating, 1/2" per pole Duplex type breaker requires 1" per breaker. 120/240 volts, AC.. 10,000 AIC interrupting rating. Thermal magnetic 40 degrees C breakers have rejection tab feature, allows only 42 circuits in the panel in compliance with NEC article 384-15. Interchangeable will replace: New General Electric, Murray, ITE (except Pushmatic), Bryant, General, American, Crouse-Hinds, Sylvania, Challenger and Westinghouse Type BR.