Product Details: Ensure your semi is Ready for the Road Ahead™ with enhanced fifth wheel security, with the Jost 12" Center to Center Composite Sliding Fifth Wheel Air Cylinder. To prevent trailers from rolling away or disconnecting, this replacement actuates the locking mechanism of the fifth wheel assembly. Engineered with a maintenance-free pivot to eliminate routine lubrication requirements. FleetPride is your First Click in Heavy Duty®.