SuperSprings are designed with various shackles. The shackles will have 1, 2, or 3 bolt holes. The bolt holes allow the installer to adjust the SuperSprings. The higher the hole, the more pre-load tension, allowing the SuperSprings to start higher on the spring rate curve. This is useful for applications with uneven loads; for example, crane trucks. The SuperSprings on the crane side of the truck can use the upper bolt holes, while the off-crane side SuperSprings use the lower bolt holes. These bolt holes, and the varying positions, can also be changed by an installer to accommodate varying ride quality preferences.