Pneumatic seals are used in a variety of applications, such as pumps, valves, and cylinders. They are designed to provide a tight seal between two components, thereby preventing air, gas, and fluids from leaking out. Pneumatic seals are usually made from rubber or plastic, and often feature a spring or O-ring to ensure a tight fit. Pneumatic seals are often used in combination with other components, such as gaskets and O-rings, to create a complete sealing system.