This ring is the wiper element for the hydraulic cylinder rod on the grain harvester header. It sits in the groove at the cylinder's rod end, where it scrapes contaminants from the rod surface as the rod retracts into the housing. A worn or damaged ring allows dirt to bypass the rod seal, leading to scoring of the rod surface and internal seal leakage. The ring is manufactured to match the original groove dimensions, ensuring proper contact pressure against the rod without excessive drag. During cylinder reassembly, inspect the rod surface for scratches and replace the ring if any wear is visible.