Hi-Lo Suspension Kit Includes all four Hi-Lo trumpets plus the two extended aluminum struts required for the rear. Many people will tell you why you should consider upgrading to the classic "Hi/Lo" suspension so I should not be bashful in giving my opinion! The best reason is for balance! The total adjustability of ride heights allows you to very accurately balance the corner weight of the car. This is very important if precise handling is your objective! Yes, I will admit that all the classic reasons also apply: "It's neat and I want it!" "It's easy to change ride heights" "It was designed years ago for Special Tuning rally program" "It allow you to some what compensate for too old rubber cones" The early designed kits required the use of a special long handle allen wrench to adjust, most modern kits no longer need special tools. C-STR644 is just such a kit. Easy to install and adjust!