Tandem Circuit Breaker, Stacked style, or Piggyback style.
Piggyback style:
Or Stacked style
Normal side-by-side.
https://www.homedepot.com/s/tandem%20circuit%20breaker%20stacked?NCNI-5
Piggyback style:
Or Stacked style
Normal side-by-side.
https://www.homedepot.com/s/tandem%20circuit%20breaker%20stacked?NCNI-5