The John Deere R543986 O-Ring is a genuine OEM sealing component designed for a wide range of John Deere agricultural, construction, and industrial equipment. This O-ring has an inside diameter of 21.82 mm (0.859 in), an outside diameter of 26.97 mm (1.062 in), and a thickness of 2.62 mm (0.103 in). It provides a critical seal in hydraulic and fluid systems, preventing leaks and maintaining optimal system pressure. This part supersedes R26288 and is essential for maintaining the integrity and performance of compatible John Deere machines.