Prefabricated helical staircase made of reinforced concrete clad in a dark brushed Matrix Marble. The staircase has rounded and classical shapes. Self-supporting steps are fixed on a rounded wall and are complemented by an elegant and simple railing and gilded wrought iron handrail, keeping the classic style of the entire structure. The stair platform is dovetail shaped. The spiral staircase is very comfortable, the durable materials are of the highest quality.