The AS568-465 18" ID x 18 1/2" OD x 1/4" SIMRIZ SZ495 O-ring by Freudenberg-NOK is designed for optimal sealing performance in industrial applications. Made from durable SIMRIZ material, this O-ring offers excellent resistance to a variety of chemicals and temperature extremes. With an inner diameter of 18 inches and an outer diameter of 18.5 inches, it meets AS568 specifications, ensuring compatibility with standard fittings. The 1/4" thickness provides a reliable seal, making it ideal for hydraulic and pneumatic systems, while its adherence to industry standards guarantees long-lasting performance.