STREET BASIS Z is strictly a ride height adjustable kit. This makes it a perfect setup for the daily driver looking for an increase in handling performance without compromising comfort for everyday use. For many of you considering a lowering spring + performance shock absorber combination, the STREET BASIS Z makes even more sense as we select appropriate spring rates and valve our dampers to match. No guesswork on the end-users part in trying to match one brand of springs to another brand of shock absorbers. The added height adjustment feature allows the end-user the ability to adjust ride height to their preference, something that lowering springs lack. Being that most vehicles are slightly unbalanced from left to right sides, that means you can easily adjust the ride height so that each corner is even from their opposing sides.