These precision devices allow the spring end coils to tilt up to 4 degrees as the spring is compressed, reducing the bending loads on your shocks.
Hydraulic perches have proven themselves on the track. Having a hydraulic perch at one end of the spring will reduce shock bending loads significantly; however, hydraulic perches at both ends of the spring will provide optimum performance.
These universal add-on perches fit most coil-over shocks using 2", 2.25"ID springs. They are designed to be used in conjunction with your existing spring perches. Just slide the hydraulic perch onto the shock and fit it between the spring and your existing perch.