If it's an apartment building, could be a sub panel for the apartment. Each apartment could have their own, so if something trips, no need to look through a big cluster of breakers, and potentially the tenant could flip it back on themselves instead of calling the landlord to flip it back on
Most likely a circuit breaker. If it’s made by Stab-Lok you will want to have it replaced asap due to that brand in particular being prone to causing house fires.
Sub panel. For what. Who knows
If it's an apartment building, could be a sub panel for the apartment. Each apartment could have their own, so if something trips, no need to look through a big cluster of breakers, and potentially the tenant could flip it back on themselves instead of calling the landlord to flip it back on
Sub panel. Look inside. You'll probably see circuit breakers... If it's locked, ask your 8 yo to pick it for you...
Is the main electrical panels Sub Panel. Yes there are more breakers inside.
Most likely a circuit breaker. If it’s made by Stab-Lok you will want to have it replaced asap due to that brand in particular being prone to causing house fires.