These inserts replace the polyurethane bushings in the Factory Five front lower control arms manufactured since January of 2004 and all of the IRS control arms for the 2015 and later Mustang based rear suspension.  They include an outer collar that is held in place with a snap ring, an inner spherical joint, and the inner spacer sleeves to make them a direct replacement without any modifications to the control arms or chassis.  These inserts provide better suspension control and consistency due to eliminating bushing flex.   They also improve shock and spring control due to less friction in the control arms, In the front end, they help with steering response and feel.  Perfect for a race car, track day car, or even a dual purpose street/autocross setup, but there is some added ride stiffness on the street due to the poly bushings being eliminated. 

Note: Sold individually. Set of four (4) required for front lower controls.