I have one of these thin dual circuit breakers Can I only

This component is suited for homes that can't accommodate tandem circuit breakers, which allow two circuits to be controlled from one slot

a single tandem breaker That breaker slots or even replace two single slot breakers with a tandem breaker

two slot toaster Take a look at the photo below You can see that the back of these two breakers has two completely different slots These slots go into a bus bar exclusively

two slot slot This key will unlock a series of other key slots , each containing one breakers so that they cannot be opened until after the oil circuit breaker