When I first got the filter I noticed that the opening of the filter was the same a the opening on the intake tube. I was going to return it but I found a plastic tube that fit into the air filter and intake tube perfectly. I also had to cut of one or two plastic tabs off my air box so the filter would fit. I had to use two clamps to hold it but I have had no problems with the air filter falling out or leaking. The preformence is not changed because i do not have the top cover off but its does a better job of keeping dirt and dust out of my engine.