An Iconic Humbucker in Rail Form The JB humbucker, arguably Seymour Duncan’s most famous pickup, gets an impressive rail-designed revamp in the form of the SH-4 JB Rails. Packing in the original JB’s fantastic top- and bottom-end power with its boosted upper midrange, the SH-4 JB Rails is already off to a hot start. Then factor in a beautifully balanced rail design that showcases each string across an Alnico VIII bar magnet to perfectly account for all frequencies, and you’ve got a smoking hot recipe for delivering clear, even, and articulate tones with excellent sustain. It makes a perfect match for Seymour Duncan’s Jazz Rails neck pickup. You’ll notice a corresponding boost in top-end definition or a slightly mellower tone when paired with either a 500k or a 250k volume pot, respectively. Carefully handbuilt at Seymour Duncan’s factory in Santa Barbara, California, the meticulous internals of the SH-4 JB Rails