Siemens type QPP, QPPH, and HQPP breakers are intended for use in Siemens panels and multi-family metering products where specified. Check the panel's wiring diagram for acceptance. 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.