The ContiTech Air Spring 64573/3B12-329&315 ensures you are Ready for the Road Ahead™ by keeping heavy duty truck bodies at a fixed distance from the road. This heavy duty air spring guarantees security and protection for any type of load. These air springs also offer the ability to lower or raise the truck's body height to match a ramp's elevation or to set up a compatible platform. FleetPride is your First Click in Heavy Duty®.