This is a factory style overdrive damper for the Ford 5.0L Coyote engine. It features a 7.75" diameter 8-rib design that delivers maximum traction and stability in supercharged applications. Can also be used with 6-rib applications. It's an ideal solution for any supercharged application where a smaller pulley is not an option. This is the same dampner used on our E-Force Coyote crate engine. This damper is SFI approved and recommended for supercharged applications only.