MATERIAL: This toilet seat fastener set is made of plastic, rubber and heavy duty 304 stainless steel. Exceptionally superior strength and stability to secure your toilet seat. Durable, rustproof and anti-corrosion, superior to most plastic fasteners. Unique Design: Plastic plates are less likely to rust than metal plates. When you tighten the screw, the washer will be pushed into the hole, you should be careful not to overtighten the screw and push it into the washer. The screws have solid brass threads inside and are not prone to rust. Easy to Use: Installation is simple and quick, just insert the rubber nut into the hole, then insert the screw into the rubber tightening nut through the washer and the plastic plate, tighten the screw, align the pin with the stainless steel base. insert into the toilet seat mounting hole Wide Application: These toilet seat accessories are universal and fit most standard toilet seats with top hinges. (The detailed dimensions of each toilet seat nut are as shown in the picture, please measure before purchasing to ensure that your toilet seat can be used properly) The toilet seat installation kit is ideal for replacing damaged or old toilet seat hinges. Note: Due to the light and screen setting difference, the item's color may be slightly different from the pictures. Please allow slight dimension difference due to different manual measurement.