Powerpact™ H-Frame circuit breaker accessory, S37449 and it offers proven performance, flexibility and reliability. Design for safety of people and property by specifying shunt trip circuits for remote emergency-off operation or under voltage release coils to protect equipment. These contacts feature auxiliary operation of early-break/early-make with clip-on mounting. compatible for Powerpact™ H, j & L-Frames, Compact, multi standard & EasyPact. certified to UL, CSA, NOM, IEC, & CCC Standards.