We believe most installs do not need a spring. However, if you are in extreme environments and need more flexibility, this HD spring from FireStik should do the trick!.
This is Firestik's all-stainless HD spring. If you are using your Jeep on trails where the antenna is hitting different objects, then you should probably consider this spring. Installation is super-easy. Simply un-screw your antenna, thread the spring on, then thread your antenna into the top of the spring. The spring is 100% compatible with ALL of the Cool Tech mounts. You can also use the spring in conjunction with the quick disconnect if desired.