High quality: zinc alloy hinges, rustproof, antibacterial, zinc alloy hinge, silver plated surface, for MDF toilet seat, wooden toilet seat, resin toilet seat. Corrosion resistance: small screws are corrosion resistant stainless steel, ideal for humid or low airflow environments. Washers and Nuts: Washers and Nuts: Rubber, The rubber washers make a large and durable rubber mounting nut with limited space.Easy Installation: This set comes with all fittings and should install easily, everything you need is a screwdriver.Zinc alloy toilet lid can be used for a long time, no oxidation, corrosion, easy to clean. zinc alloy, rustproof, antibacterial, electroplated surface is not easy to fall off. Perfect for use in bathroom, hotel, public places, etc.