I was cleaning today my two air filter boxes. One is take of mine bike 1998 model and one is from an earlier model. And I`ve seen a difference. Don`t know how to explain but on 1998 model I have one more opening which is broken, has no sens having it and don`t know what is it for.

Upper one is from 1998 model and it comes right here

And another picture:

Can anyone explain what is it for? Should it be there or should I use previous model one and that`s it?