This ball center is for use in all RockJock 2" diameter Johnny Joint® rod ends. Ball is CNC machined steel, heat treated, features a .500" thru bolt hole and is a 2.000" wide mounting width. For use as a rebuild part or for those building up their own arms and joints. We use this center in our Johnny Joint® front upper control arms for the '07 and up Jeep JK. Sold each.