This is an optional Traxxas WideMaxx Steel Constant-Velocity Driveshaft Set. This is a complete upgrade, with steel constant-velocity driveshafts, bearings and outdrives. These parts are intended for use with the Traxxas WideMaxx or the Traxxas Maxx equipped with the optional WideMaxx suspension kit (TRA8995). These parts must be combined with 17mm splined wheel hubs (TRA8654) and 17mm nuts (TRA7758) to complete the installation.