When replacing an aerator to a kitchen or bathroom sink, you cannot easily install a new one. What is the problem?
Possible solution #1
There is a gasket attached to the new aerator that needs to be removed.
Possible solution #2
The new aerator is a male aerator and you need a female aerator.
Possible solution #3
The new aerator is a female aerator and you need a male aerator.
Possible solution #4
The new aerator is not the correct size.
Possible solution #5
The old aerator *appeared* to be a male or female aerator but it was BOTH male and female.