They are constructed with a durable monotube shock design featuring a 52mm carbon steel body and a high-performance internal piston for fast and precise damper response. The springs are crafted from SAE9252 steel, ensuring both comfort and high performance. To maintain optimal damper performance in all conditions, race-quality shock oil is utilized. This set includes four coilovers with 16 levels of adjustable damping, allowing drivers to tune the suspension from soft to firm settings. Crucially, ride height adjustment is independent of spring preload adjustment, offering greater flexibility in tuning the vehicle's stance and handling. The shock bodies are anodized for durability, and the mounting brackets are constructed from a combination of lightweight aluminum and T7075 forged aluminum or carbon steel. Installation of these true rear coilovers requires specific modifications. Because the factory rear suspension uses a divorced spring design, the factory rear toe arm must be replaced with a bucket delete toe arm. The Godspeed AK-190 bucket delete rear toe arms are sold separately and are mandatory for proper installation; the kit should not be installed without them. Fitment is specific to RWD models, including the Infiniti G37 Coupe (CV36) and Sedan (V36) from 2008-2013, the Infiniti G35 Sedan (V36) from 2007-2008, and the Nissan 370Z (Z34) from 2009-2020. This kit does NOT fit AWD G37X models, the G37 Convertible, or any model equipped with the 4 Wheel Active Steering (4WAS) system. A professional wheel alignment is required after installation to ensure proper handling and tire wear.