I appreciate this is now an old post, but I have come across the same situation! The parts diagram doesn't show a cage and filter separately? Someone has obviously been tinkering with the box on my KDX, although it fits it's not like any I have seen pictures of

It has a cut out at the rear edge of the box with a bodgy piece of gauze crudely stuck on! I'll try to post a picture later to see if anyone can identify what it is!?
There is no clip on the exit hose to air box and a filter basically thrown in without the cage

