The S4 has a "rail" design 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. Great for heavy rock. All HZ Pickups have EMG's exclusive 5-wire quik-connect output allowing any number of wiring combinations, and are fully shielded for a minimum of noise. String grounding is recommended to further decrease noise.