Cutler Hammer has their "Classified" series of circuit breakers, that are designed to replace the 1" width SqD Homeline, Crouse Hinds, GE, Siemens/Murray, and T&B breakers.
They also produce a 3/4" version, designed to replace the SqD QO series.
https://www.platt.com/CutSheets/Eaton%20Distribution/Breakers-ClassifiedType.pdfNote that they aren't UL listed, but UL Classified.
I think the BR is only listed for use in Cutler Hammer panels.
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