Xray have announced new springs for the XB4 that have been specifically designed to complement the big bore shocks. Sold as a pair, the spring rate of the linear springs is constant during the entire spring compression, while the main advantage and benefit of progressive springs is that as the car initially enters the corner they work like soft springs to provide maximum traction. At the same time, when the chassis begins to roll, in the middle of the corner, the spring rate progressively increases until they work like a hard springs which allows the car to maintain maximum cornering speed. Like all the other Xray springs, these springs are manually measured, selected and matched into pairs to guarantee precisely equal length and damping characteristics. The front springs are available in Progressive (2 stripes) and linear (2 Dots & 3 Dots) while the rear springs are available in progressive (2 stripes) and linear (1, Dot, 2 Dots & 3 Dots).