X-Rings, also known as Quad Rings, are four-lobed double-acting seals that can be used in a wide variety of static and dynamic sealing applications. Quad rings can be considered as a valid alternative seal solution to standard O-Rings, they have the same dimensions as the standard AS568 O-Ring sizes and the four-lobed cross-section has the advantage to prevent the seal from twisting and rolling. Along with higher stability, Quad rings are also considered to have a better sealing efficiency compared to conventional O-Rings. Mainly used for dynamic applications, Quad rings result in a longer seal life and offer a lower friction as the fluid trapped between the lobes provide a more efficient lubrication to rotating and sliding surfaces. Quad Rings are readily available in nitrile rubber (NBR), other compounds such as fluoro rubber (FKM, FPM, Viton) are available on request.