The metal part of the Fontanot Arkè Civik Zink prefabricated staircases is protected with a zinc coating which makes it particularly suitable for outdoors. The handrail of the zinc-coated spiral staircase is in black PVC . The nuts and bolts are in stainless steel for better resistance to atmospheric agents. Civik Zink is easy to assemble, adjustable in height and purchasing some extra items can be as high as 376 cm.