... by 216pcs 5mm N35 magnet balls 2)Nickel,gold,black,silver,green,blue,red 4)4.8mm,5mm,6mm,7mm,8mm,9mm ... ) Surface treatment:Coating Nickel-Copper-Nickel (NiCuNi) coating with nickel,silver,gold, black nickel.blue,redMagnetic power(N35grade):5mm 5000-5300guass ...