yes the stock filter has a cone shaped plastic thingy, with you buy the K&N single filter it tells you to cut the coned end off leaving just the flat part that slides into the groove. It can be difficult at times aligning it into the slot, I noticed one day that it wasn't seeling properly at the carb. side.
So I bolted it in permanetly.. The K&N can still be removed via the hose clamp... Still confusing? No offense takin..