This photo shows the internals of the 2 5/8-inch version of the RRD shock setup as a coilover. Notice how the upper portion of the shock body has threads cut into the exterior fluting; this allows for installation of a threaded spring seat or adjuster as well as a stop ring for dual spring-rate arrangements. The 25/8-inch RRD shocks come standard with 1-inch shock shafts made from Nitrotec steel material. What is neat about these larger shock shafts is the fact that they are hollow, allowing for additional oil volume inside the shafts. This effectively increases the shock's cooling surface area to that of a standard 3-inch-diameter shock body. Additionally, this setup allows the shock to hold the same volume as a remote-reservoir shock without the packaging limitations of a remote reservoir-a good thing for late-model pickups that typically have less space for such products. All RRD racing shocks feature genuine Amsoil Shock Therapy hydraulic fluid.