These spacers mount on top of your upper strut mount or caster camber plates (1 per side) to raise the vehicle approximately 3/8" to 1/2" (0.425" average)
If you want to raise the vehicle more, add a kit in the dropdown for an approximate 0.850" total rise. In this configuration you will be stacking (2) spacers per side for a total installation of (4) spacers.
This method is most commonly needed when people use a light rate drag spring and need to raise the car after adding weight from a power-adder, or when someone uses soft springs for street / no-prep use and wants to raise the car up to then lower the spring down (to compensate) to help add shock stroke travel.
NOTE: If stacking 2 spacers per side, you will need check available threads on your upper mounts / caster camber plates. In some cases, longer studs might be required. In most cases a lower profile nut is suggested.