The John Deere R308486 is an authentic OEM back-up ring, also known as an anti-extrusion ring, designed to provide essential support for O-rings in various John Deere hydraulic applications. This critical component prevents O-ring extrusion under high pressure, enhancing sealing performance and extending the lifespan of hydraulic cylinders and other components. With an inner diameter of 25.4 mm, an outer diameter of 31.75 mm, and a thickness of 1.6 mm, this ring is manufactured to John Deere's rigorous specifications, ensuring optimal fit and reliable operation in compatible machinery.