Subaru IMPREZA WRX STI SED/WAG GRB 2011-2014 0.6F/0.6R Swift Sport Springs 4F907R. 6kg Fr / 7.2kg Rr. Sold in a set of four springs. Made in Japan. Swift Spec-R Springs are built for track duty. Swift Spec-R springs are designed at the upper limits of the OEM shock valving. Track tested and tuned for optimum performance yet comfortable enough for a daily driver. From HPDE events to SCCA competition, Swift Spec-R Sport Springs are made for the track enthusiast looking to take their vehicle to the next level. Swift Spec-R Sport Springs were engineered with 3 characteristics in mind – Modified ride height compared to Sport Springs to maximize optimal suspension geometry – Further increasing the spring rate to enhance overall performance. The increase in spring rate is based on the upper limits of the vehicles factory shock valving – Maintaining optimal comfort level for street use. Spec R springs are wound with the same engineering and material as our sports springs. With the exception of stiffer rates and slight change in ride height; you can expect the same characteristics as our sports springs.