Filter question?

[TheRussianBull]

I have a question about a filter... now im waiting on my AEM CAI to come in the mail, gonna install it myself, me and the team installed my friends intake into his Rolla, man, that thing sounds like a beast and pulls like heck, but i was roaming through autozone lo, and i see this breather filter:

http://www.autozone.com/select...p.htm

Can anyone tell me whats it for, and where it goes (hopefully with pics) and does it improve anything?

[Johniboi]

You should be recieving a filter with the aem intake, so i wouldnt worry bout purchasing another one..