This sealing ring fits the rod end of the hydraulic cylinder on a large square baler. It prevents fluid leakage past the rod gland during extension and retraction cycles. A worn or hardened ring allows external oil seepage, which reduces system pressure and can contaminate the bale chamber. The ring is sized to match the original groove geometry so that the wiper seal and rod bearing maintain their correct axial clearance. On reinstall, lubricate the ring and rod surface before assembly.