Material: The toilet seat hinge fasteners are made of PP and stainless steel, resistant to dirt and wear, not easy to break. Metal screws are not easy to rust thanks to the protection of PP and are durable. EASY TO INSTALL: The plastic stoppers have a threaded part, so you can easily insert them into the hole on the top of the toilet. When you tighten the screw, it will expand and be pulled into the hole, without having to re-tighten the other side. Wide range of applications: Reliable mounting kit specially designed for toilet grab bars. The toilet lid accessories fit most standard toilet seats with top-mounted hinges. Convenient and time-saving. The toilet lid and top-mounted seat hinges are only required to be installed once and will last for years.