... 3.Material:Kovar(4J42,4J29) 4.Finish:Gold/Ni/Silver plating Fiber Optic Precision Metal Component-shaft with ... Gold/Ni Plating Material availableBrass,Copper,Kovar,Invar,WCu,Stainless steel ... , Aluminium, White/Black Delrin etcFinishGold/Ni/Silver plating, Bkackening, Anodization, Passivate, Sand Blasting, Polishing ...