N42 disc permanent ndfeb magnet 1.grade: N35-N52,(M,H,SH,UH,EH) 2.ceritfication:ISO9001:2008 / SGS 3. ... bar.20 days,average low weight loss less than 2 mg/cm2 Sintered Neodymium Magnet applications:loudspeakers,motor assemblies,windmill,Home ... your test. N42 disc permanent speaker ndfeb magnet N35-N52,(M,H,SH,UH,EH)