If it's not there and you want to save a $10-15 dollars you can just buy the plastic housing. Usually runs around $15. Take it to an auto parts store and match it to a stock air filter. With a little trimming I believe a FRAM 3019(?) will fit. They're only around $5-6. You won't get any activated charcoal and you may get a little "rubber" smell from the seal material for a while. After all it's an engine air filter and the engine really doesn't mind the smell. But if all this stuff just seems like a big waste of time just go ahead and spend the extra $20 and get the air filter along with the upgrade kit.