Originally Posted by Seeria
What is the name of that cover, Smitty?
I don't know the technical name, but the slang term is "mouse hole." It isn't really an "outlet" in electrical terms, since it is just a cord pass-through and has no connectors, but it is an "outlet" in the sense that the cord gets out from the inside.
To use it, you swing the trap door open and pass your male cord end out or female extension cord in. The flexible fingers (barely visible on the inside edge)hold the cord loosely in place. Then move the slider on the cover up, and close the trap door over the cord, and move the slider down to make the hole only big enough to fit the cord. When the cord is not in place, move the slider all the way down to close off the hole.
If the male connector on your inside cord isn't too big, it can live in the tube between the fingers and the trap door when not in use.