I bought the filter for the fd and its way too big, it will slip on to a 4" inlet on a turbo. The core dimensions are 5"x9" with the silicone end, its over 10" long.
I paid $60 shipped, looking to get $45, it was never used. I’ll try to post pics later.
heres a pic from the aem site
aww man 4" i got excited when i saw the title i want one of them