Introducing Isky's new RAD-9000 process option for Tool Room valve springs. Under trade secret Radial-Densification (RAD), the physical properties of Tool Room springs are optimised for even greater surface to core uniformity. To insure they'll withstand the tortures of sustained high rpm operation, we subject each batch to the most rigorous real world test standard ever created, SPINTRONTEST II. It's a no holds barred run as high as 9000 RPM where for over 1,000 miles, race ending competitive abuse is continuously revisited. This pass or fail benchmark is the only test of its kind in the performance industry and every set of Tool Room springs conforms to its high standard.