EXCLUSIVE WINDTUNNEL DESIGN Windtunnel "PRO" CS Barrel Shape Center Shock Springs.

The barrell shape design is unique to Windtunnel Racing.  These springs have been  specially engineered and designed with a combination of shape, wire size, diameter and distance between coils, which provides a smoother feel (as compared to a standard or commonly used progressive type spring) to your race car especially on rough or bumpy surfaces.