Seymour Duncan SMB-4A Alnico Music Man Replacement Pickup - Black SMB-4a MusicMan Alnico Bass Pickup The Alnico magnets, together with unique coil windings, have the effect of extending both ends of the frequency spectrum beyond that of the ceramic magnet version In other words, the Alnico version is both warmer on the bottom and more detailed on top Comes with four-conductor hookup cable and logo cover The Alnico magnets, together with unique coil windings, have the effect of extending both ends of the frequency spectrum beyond that of the ceramic magnet version