The Hitachi 4424516 is a genuine OEM oil return ring designed for the swing mechanism of Hitachi EX300 series hydraulic excavators. This critical component ensures proper oil sealing and efficient operation within the swing system, preventing leaks and maintaining hydraulic integrity. Manufactured to Hitachi's stringent quality standards, it guarantees precise fitment and reliable performance for models including EX300, EX300-1, EX300-2, EX300-3, EX300-5, EX300LC, EX300LC-3, EX300LC-5, EX300H-3, EX300H-5, EX300LCH-3, and EX300LCH-5.