b ruckh, it's just exhaust pipe...that's what mine is, you just have to make sure you paint it inside and out so it doesn't rust.
Brandonmag, I've been running an AEM Dryflow cone filter basically since I put my truck on the road almost 20K ago. K&Ns and the like let in a lot of fine dust, the Dryflow has a finer media on it and is a better all around filter (but it costs more). Haven't noticed anything unusual on mine.