Material: Stainless steel AISI 316.Treatment: Double factor electrolytic polishing. Shaft: The shaft of ROCA hinges is a calibrated tube finished off at its ends with two special edges, to give a safe and resistant joint. The logo engraved on these edges is your guarantee, and ROCA fittings are the only ones to be electrolytically polished. The electrolytic polishing is a procedure to give brightness, eliminate the impurities of the metal and achieve an exceptional finish, by removing a thin layer of its outer surface. The electrolytic polishing has great benefits: it confers a great resistance to corrosion, including the one that originates by the difference of potential of metals, improves the aspect and obtains a greater brightness when disappearing the micropores. Less risk of adhesion and less friction.