STREET ADVANCE Z takes the ride height adjustability of the STREET BASIS Z line and adds 16-way damping adjustment. So, not only do you get a matched spring and damper setting, you now have the ability to tune the dampers to meet your driving conditions. Roads seem a bit rough? Soften up the damping. Glass smooth highways? Crank the damping to a stiffer setting. You get all that and everything in between. STREET ADVANCE Z is also compatible with our EDFC systems (some STREET ADVANCE Z coilover kits may require extension kits for compatibility), giving you a completely adaptable suspension kit based on your driving conditions/characteristics! Thats a feature that not even all sports luxury cars have, and our setup is at a much more affordable price