The 'shroud' section is exactly 4 inches.
Yeah It does say spyder threaded but it appears to fit on my 06 etek which has autococker threads, you might want to get it double checked just in case.
I can check it against my Creed as well and let you know.
I'll go for £20 payment owed, if you're still interested drop me a pm and I'll get back to you with the paypal addy.