Associated package of four replacement 10-32x5/16 set screws for the suspension arms on the Nitro TC3 are constructed of black steel. Hexagon socket drive. These set screws are referred to as "droop screws" in the manual for the Nitro TC3. The modeler can adjust the the height on the suspension arms by either tightening or loosening these set screws. One set screw goes in each suspension arm.