Name: n45 large ring neodymium magnets for speakers with dia. 3 up to 220mm. TS16949 & ISO14001 Certified. Short Lead-time Product Name: n45 large ring neodymium magnets for audio equipments Features:1) φ3 up to 220mm2) Up to N52 max.3) Ni, Zn, NiCuNi, Gold, or Epoxy coated.4) Max. Working Tempeture: 250 deg. C5) Used in audio equipment, such as Loudspeakers, earphones, microphones,etc.