The sinuses are air-filled cavities. 1  They are located: 2  Within the bony structure of the cheeks. 3  Behind the forehead and eyebrows. 4  On either side of the bridge of the nose. 5  Behind the nose directly in front of the brain.
An O-ring is a round ring that is used as a gasket for sealing a connection. O-rings are typically constructed out of polyurethane, silicone, neoprene, nitrile rubber or fluorocarbon. These rings are commonly used in mechanical applications, such as pipe connections, and help to ensure a tight seal between two objects. O-rings are designed to be seated in a groove or housing that keeps the ring in place. Once in its track, the ring is compressed between the two pieces and, in turn, creates a strong seal where they meet.
The rings are ideal for all Mixed Martial Arts, Grappling, and Kickboxing. These rings are made with structural steel, for the ultimate strength and safety. Nobody can give you a stronger ring! This is a MONSTER RING! While other companies offer a difficult assembly with nuts and bolts, using cheap tubular steel, that often results in a very unsafe and unstable ring, we build our rings out of STRUCTURAL STEEL for the absolute strongest and safest ring available.