... -N38-N40-N42-N45-N48-N50-N52 3)Nickel,Zn,ni-cu-ni coating block permanent magnet block ndfeb Magnet is the most ... ,diametrically,multi-pole magnet disc.3)Ni,NiCuNi,Zn,Black Expoxy,Black Nickel,Ag,AU,etc coating.4)Application:Acoustics,Motors,Windmill ...