EMG S4 Passive Rail Single-Coil Replacement Electric Guitar Pickup Great for heavy rock Rail design with ceramic magnets and a solid cover cap Has a balanced sound with the crisp highs of a traditional single-coil The S4 is a rail-design pickup with side-by-side coils, a ceramic magnet, and a solid cover cap It's not overwound like most rail pickups, for beefier low-end and midrange, but has the crisp highs of a traditional single-coil pickup