Siemens D115 QO Replacement 15-Amp Single Pole Circuit Breaker Product Description Siemens QO replacement breakers are UL listed for use in Square D QO brand load centers and are ideal for replacement of existing breakers or if expansion circuits are required. These 3/4-Inch breaker snap on to the QO type bussing. Siemens strongly recommends against the use of "used" breakers. The installation of used breakers in a Siemens panel will void the warranty on the panel. Siemens does not sell used breakers and has not approved any 3rd party sellers to do so. From the Manufacturer Siemens QO replacement breakers are UL listed for use in Square D QO brand load centers and are ideal for replacement of existing breakers or if expansion circuits are required. These 3/4-Inch breaker snap on to the QO type bussing. Features 15-Amp QO replacement 3/4-Inch Frame Plug in type UL listed USA SHIPPING estimates delivery times and we work to get your item to you as quickly as possible and within those times, but please know it may take slightly longer than the estimate.