Moog CK620381 Control Arm and Ball Joint Assembly New design with pre-installed integral dust boot provides easier installation while still maintaining the same level of performance Problem Solver powdered metal gusher bearing design enables grease to flow through the bearing to the stud for reduced friction and enhanced strength and stability Hardened ball stud withstands higher loads Premium forged housing with an increased cross section provides strength and durability Larger grease reservoir and easy-to-install pre-tapped grease fitting hole for improved maintenance Time-saving pre-installed integral dust boot is made from higher strength materials for longer life