... 2)nickel,black,silver,gold 3)SGS certified Features of magnetic sphere:1)Mateials: NdFeb magnet2)Colors: nickel, black,silver ... Quantity:216 pcs/set4) Packing:Round steel box packing1. The magnetic sphere has high remanence, high coercive force, high energy product ... coercive force6. For most applications, coating or plating is recommended.7. Coatings: Ni, Zn, gold, copper, epoxy, chemical, parylene ...