This 1:35 scale item is a set of "banjo" or Corporation axles to convert the Tamiya truck from Timken axles (as supplied).  These replace the kit axles and add the option of posable steering.  Some minor surgery to the kit's drive shafts is required.  Note the parts are sprued together for convenience of the printers and packers at 3dptrain, so will need separated and cleaned up.