LevelPRO® ride height sensors upgrade your existing RidePRO® pressure-based system. The ultimate air suspension management system measures BOTH pressure and ride height. With the addition of LevelPRO® ride height and spring balance (loads) are established by comparing the position of the ride height sensor to the air pressure within each air spring. Your car is leveled with no crossloading. This is especially important for dynamic driving scenarios where quick transitions occur. Examples include high performance driving, sudden directional changes and panic stops. Pressure-only systems are good at handling these load changes, but combined pressure and height systems work best. The complete LevelPRO® kit is easy to install. The complete LevelPRO® kit includes: 4 Height Sensors 4 Height sensor linkage kits (with steel linkage rods and rubber rod ends), Group harness, 1/4" sensor bolts w/ Nyloc nuts & flat washers, mounting tabs, Heat shrink tubes and Installation Guide. NOTE: LevelPRO® sensors can only be used in conjunction with RidePRO® Digital Control System.