The guy I bought it from (
FS: Extender/detuner with "F" logo, Dimarzio Model P) thinks it's a BT-8. Can't confirm that, but I can tell you it DOES NOT fit an 08 American Standard bass.
It has the Fender F stamp.
I'll trade for the BT-4 or any other that fits an 08 Am Std with no mod needed.
Sale price is $40 shipped.