... certification:SGS,ISO9001 Coating:Nickel magnetization:according to you n speaker magnet mainly comprised of neodymium ,iron and boron,is the ... properties of high remanence,coercivity,and Max.energy product. speaker magnet grade:N35,N38,N40,N42,N45,N48,N50,N52(Max ... N30AH,N33AH,N35AH(Max.operational temperature:up to 230c) speaker magnet Outsanding product:1)high performance:N52,N48M,48SH,42UH,38EH ...