Rear Coil Over Shock Absorber, Magnum Series, Competition Engineering's Rear Coil Over Shocks are a part of our Magnum Series, a line of professional-grade products engineered for maximum performance and durability. They feature 12 settings, allowing you to tune the suspension from soft to firm woth a simple turn of the knob. All Aluminum billet housing is CNC machined with a black anodized body, Spring seats are adjustable for preload and accept 2-1/2 Inch I.D. Springs, 5/8 Inch hardened chrome piston provides superior strength