A rubber O-ring seal is a torus-shaped mechanical sealing element used to prevent fluid or gas leakage between mating surfaces. It is widely used in industrial, automotive, hydraulic, and pneumatic applications due to its simple design, durability, and cost efficiency.

Manufactured from elastomers such as NBR, EPDM, silicone, Viton®, and neoprene, O-rings deform elastically when compressed in a groove, creating uniform contact pressure. This action forms a dependable, leak-proof seal that performs effectively under varying pressures and temperatures.