The F-Spaced Imperial® features the same specs as our Imperial® Humbucker but with wider pole spacing to accommodate the Fender bridge position or guitars equipped with a whammy bar. (Pole spacing is 2-1/16" center-to-center of the two outside poles. Read more about F-spacing HERE). Imperial F-spaced pickups are available in a wide range of color options and wiring is 4-conductor only.