This 175 Amp main breaker kit is intended as a replacement for main breakers installed in the Siemens EQ series of load centers. The kit can be installed on Siemens EQ 200 Amp main breaker load centers. The production of EQ load centers was halted in 2002, being replaced with the Siemens Ultimate series of load centers. This kit will not fit on the Ultimate, ES, or PL series of load centers. Check the panel wiring diagram to determine the series type.