Ross if you look closely you can see a billet plate on the strut that's silver. That is part of the bag not the strut. The bag has upper and lower mount plates with an inner sleeve so the shaft of the shock/strut can go through it. The bag is a separate piece and you can fine tune your ride height like you can with a coil over, the bag then acts as an adjustable spring to change ride quality. The side benefit is with a ride height sensor you can lower and raise the car with the airspring.