N42 disc permanent ndfeb magnet 1.grade: N35-N52,(M,H,SH,UH,EH) 2.ceritfication:ISO9001:2008 / SGS 3. ... ,It has excellent properties of high remanence,coercivity,and Max.energy product.Sintered Neodymium Magnet gradeN35, N38, N40, N42, N45, N48 ... your test. N42 disc permanent speaker ndfeb magnet N35-N52,(M,H,SH,UH,EH)