Punch magnet 1) Anti-corrosive 2) Coating: Nickel 3) Lasting durable 4) Different performance: N35,N38,N33H,N30A Punch Magnet performance is high, and thermostable ,On its finished the drilling is to meet the different needs of customers .Through methods and so on caking or agglutination manufactures each domain appropriate product.High power ring magnet is suitable to use on loudspeaker, speaker ...