Rubber O-rings are a type of mechanical seal in the shape of a torus or doughnut-shaped ring. They are commonly made from rubber materials such as nitrile, silicone, fluorocarbon, EPDM or neoprene, that are resistant to high temperatures, chemicals, and abrasion.O-rings are used to create a seal between two surfaces in a wide range of applications, including hydraulic and pneumatic systems, plumbing, and automotive engines. They are able to provide an effective seal against fluids and gases, and are designed to withstand high pressures and extreme temperatures.