A simple but effective hydraulic suspension system on the 4Runner that balances the damping pressure inside the vehicle’s shock absorbers to maintain level ride characteristics. X-REAS stands for “RElative Absorber System,” and the “X” refers to the system’s cross-linking of the shock absorbers. That means that the right front shock is linked to the left rear shock, and the left front shock is linked to the right rear shock. Fluid flows back and forth to active reservoirs from the bottom of the front shocks to the top of the rear shocks, dampening diagonal roll/pitch motions and limiting body sway.