2-60pcs Bonded NdFeB Multi Poles Magnet Ring OD 19x12x32 mm Diametrically 8 Poles Neodymium Permanent Magnets Epoxy Coating 1 pack diametrically ndfeb magnet ring diameter 9 53x3 18x3 18 mm 3 8 1 8 1 8 tube magnetized neodymium permanent magnets