Amazon.com: Amumu NEO-SP31 Passive Neodymium Magnetic Soundhole Pickup for Acoustic Guitar : Musical Instruments
World's first neodymium pickups for guitar and bass - Q-tuner
Fishman Neo-D Passive Magnetic Guitar Soundhole Pickup with Cable
Dahrendorf Guitars - Neodymium Pickups Neodymium is a magnetic alloy such as Alnico or Ceramic (Ferrite). It's not common material yet in conservative guitar pickup industry but it already found its place