Great Planes 5/16" -24 Aluminum E-Spinner Adapter Adapter for use with 5/16 -24 prop shafts Includes (1) 5/16 -24 Spinner Adapter, (1) 30mm Socket Head Screw, (1) 25mm Socket Head Screw, (1) 20mm Socket Head Screw, (1) 13.5mm Socket Head Screw Constructed of aluminum, silver in color.