Ok, as I've said before, don't know a ton about cars, someone around here has a K&N crankcase filter they are looking to get rid of... What is it and where does it go? They say it will fit a 00 Mustang, but what does it do? The part number is 62-1490. Here's a pic...

 

Here's my guess: that gadget right there is a breather filter, attaches to valve cover. "crankcase filter" is a misnomer.

 

Yeah it will fit. Its a breather. Goes into your valve cover. Not needed or worth it tho

 

Not worth $10? What does it do exactly?