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

Remove one of the small 2 pole circuit breakers and put in a 30a or 40a 2 pole breaker and feed a sub-panel next to the current panel

Double-pole breakers are double-wide breakers that take up two slots in the breaker box They have a toggle switch that's twice the length of

two slot The advantage of this type of breaker is it only takes one slot on the panel It has two screws, one for each of the hot wires on the two

two slot shelving 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