Seymour Duncan Custom 7-String Guitar Pickup Black 7-string humbucking guitar pickup has just the right balance of power, sustain, and distortion Now available for 7-string guitars, the Duncan Custom beefs up the sound of the Patent Applied For pickup so that you get a hard-driving, kicking sound with just the right balance of power, sustain, and distortion Now available for 7-string guitars, the Duncan Custom beefs up the sound of the Patent Applied For pickup so that you get a hard-driving, kicking sound with just the right balance of power, sustain, and distortion