The RK series is a more value driven part. Because there are so many different vehicles both foreign and domestic, Moog has introduced the R-Series arms to provide replacements for a wide range of vehicles. The RK arms have OE fit and form geometry alignment, with pre-installed OE style bushings and most include the ball joints. However these ball joints are not serviceable like the CK arms. All of the R Series arms have Moog validated construction and design, providing a less expensive alternative. Product Features:Restores like-new steering and handlingMOOG engineering-validated construction and designEasy to installMOOG R-Series (RK) line of control arms are the right choice for the value-driven repairOE fit and form geometry and alignment