I changed air filters to a K & N drop in. When I took the old filter out of the filter box, I noticed another small filter looking device attached to the inside cover of the air filter box. What is this? It seemed a little dirty, do I need to replace?

 

I understand it is a breather filter for the air or whatever goes in the long black tube that runs across to the motor. Only costs a couple of dollars--I suggest replace it (there is a clip to hold it in place, then it comes out easily).
Frank