Siemens QN type breakers take up four 1-Inch spaces and are intended for use in Siemens load centers, meter combinations, and multi-family metering where specified. Check the panel wiring diagram to confirm acceptance of this breaker type. This breaker type is intended for applications in which the breaker is mounted vertically. 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.