Anyone know the diameter?

Anyone know the diameter on an AEM CAI for an '02 Civic Si?

I just got my CAI and am going to install it soon. Only problem is AEM doesn't make a bypass valve for this platform. Now I would much rather "alter" my CAI and risk the warranty on the CAI rather than risk engine damage on a new car.

So can anyone provide a link or information about the diameter of the pipe so that I can order the correct size valve? I guess I could measure it but I don't have a tape measure, nor do I want to risk ordering the wrong one by just measuring it here. I am looking for solid info that specifically spells out the diameter of the pipe.

Any help would be greatly appreciated.